Biology Flashcards
(82 cards)
1
Q
How to use a microscope to view slides. (6)
A
- Move the stage (the flat ledge the slide sits on) down to its lowest position. (1)
- Place the glass slide onto the stage. (1)
- Select the lowest power objective lens. (1)
- Turn the coarse focus knob slowly until you are able to see the cells. (1)
- Turn the fine focus knob slowly until the cells are in focus and you can see them clearly. (1)
- Repeat steps 1-5 using the higher power magnification to see the cells in more detail. (1)
1
Q
List and describe the 7 Life Processes.(7)
A
Movement (1)
Respiration (1)
Sensitivity (1)
Growth (1)
Reproduction (1)
Excretion (1)
Nutrition (1)
2
Q
Draw and label a plant and animal cell. Compare and contrast both cells (7)
A
The four key components of most animal cells are:
Nucleus - this contains the DNA of the organism and controls the cell’s activities. (1)
Cytoplasm - the liquid that makes up most of the cell in which chemical reactions happen. This is mainly water. (1)
Cell membrane - a flexible outer layer that surrounds the cell and controls which substances can pass into and out from it. (1)
Mitochondria - tiny parts of cells floating in the cytoplasm where energy is released from glucose from food. The mitochondria, found in the cell cytoplasm, are where most respiration happens. (1)
Plants cells, on top of what animal cells include, they have:
Cell wall: a tough outer layer of the cell, which contains cellulose to provide strength and support to the plant. (1)
Vacuole: a space inside the cytoplasm that contains a watery liquid called cell sap. It keeps the cell firm. (1)
Chloroplasts: structures found in the cells of green parts of plants only (leaves and stems) which contain a green pigment called chlorophyll in which photosynthesis occurs. (1)
3
Q
List at least five specialised cells and explain how they are
adapted to their function. (10)
A
Red blood cells. (1)
They don’t have a nucleus, allowing more space to carry oxygen. (1)
Sperm cells. (1)
A tail helps the sperm moves towards an egg cell.
Egg cells. (1)
The egg cell’s cytoplasm contains nutrients for the growth of the early embryo. (1)
Nerve cells. (1)
They are thin, and can be more than one metre long in your spinal cord. This means they can carry messages up and down the body over large distances very quickly. (1)
Muscle cells. (1)
Cardiac (heart) muscle cells contract and relax to pump blood around our bodies for our entire lives. They never get tired. (1)
Smooth muscle cells make up thin sheets of muscle, such as the stomach lining. They can also be arranged in bundles, or rings, like that in the anus. (1)
Skeletal muscle is joined to bones. Its cells contract to make bones move and joints bend. (1)
4
Q
Describe how organisms are organised and give
examples. (2)
A
Cell -Tissue - Organ - Organ System - Organism. (1)
Palisade Cell -
More Palisade = Tissue -
Other tissue = Organ = Leaf -
More Leaves + Other Organs = Shoot system -
Different Organ Systens make up a full Plant = Organism (1)
5
Q
Four main plant organs and how they are adapted to
their function. (1)
A
Flower (1)
Flowers have bright colours, smells and nectar which encourage pollinators to pay them a visit. (1)
Stem (1)
The stem carries water and nutrients to different parts of the plant. It also provides support and keeps the plant standing upright. (1)
Leaves (1)
A leaf usually has a large surface area, so that it can absorb a lot of light.
Roots (1)
Roots have a massive surface area for the root hair cell to absorb more water and minerals. (1)
6
Q
Nutrition, name the main food groups, giving examples and what they are needed for in the body.
A
Fruit and vegetables, for example, apples, bananas and broccoli, give us vitamins to keep our bodies working and help our immune system and fibre to help our digestion.
Carbohydrates, like pasta, bread and rice, keep our energy levels up.
Proteins, such as meat, beans, and eggs, build healthy muscles and allow our bodies to grow and repair.
Dairy, like milk, cheese and yoghurt, gives us calcium for strong teeth and bones. Many dairy-free alternatives have calcium added to them too.
Fats and oils, for example olive oil and butter, act as an energy store.
7
Q
What is meant by a balanced diet?
A
A balanced diet refers to the intake of a variety of foods in appropriate proportions, providing the necessary nutrients to support overall health and well-being. The goal of a balanced diet is to ensure that the body receives the right amount of carbohydrates, proteins, fats, vitamins, minerals, and water.
8
Q
Describe the food tests. How is iodine used to test for starch?
A
9
Q
Label the Respiratory System. Describe the role of the
lungs, diaphragm, and ribs in breathing. (7)
A
PPT 16 (1)
Lungs - Contain the gas exchange surfaces (2)
Ribs - Provide a moveable cage to enclose and protect the lungs (2)
Diaphragm - Works with the intercostal muscles to allow ventilation to happen (2)
10
Q
How the lungs and alveoli are adapted to gaseous
exchange. (6)
A
Any Three of: (6)
Large surface area - many alveoli are present in the lungs with a shape that further increases surface area.
Thin walls - alveolar walls are one cell thick providing gases with a short diffusion distance.
Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface.
Permeable walls - allow gases to pass through.
11
Q
The stages in human development from fertilised egg to
death. (6)
A
- Foetus (1)
- Baby (1)
- Childhood (1)
- Adolescence (1)
- Adulthood (1)
- Old age (1)
12
Q
The organs of the male reproductive system. (11)
A
Testes - produce millions of male sex cells called sperm
make male sex hormones (1) e.g. Testosterone (1)
Scrotum - a bag of skin outside the body where the testes are stored. (1) They are at a lower temperature than the rest of the body. (1)
The epididymis is a muscular coiled tube where sperm are stored. (1)
The sperm duct transports the sperm from the testes to the penis. (1)
The prostate gland and the seminal vesicle add fluid to sperm. (1)
The fluid and sperm together is called semen. (1)
Semen and urine from the bladder both leave the penis through the urethra (1)
The penis has 2 functions:
to pass urine out of the man’s body (1)
to pass semen into the vagina of a woman. (1)
13
Q
The organs of the female reproductive system. (6)
A
Vulva – the outermost part of the female reproductive system where the urethra is found. (1)
Vagina – a muscular tube that leads from the cervix to the outside of the woman’s body. (1)
Cervix – is a ring of muscle at the lower end of the uterus. It keeps the baby in place while the woman is pregnant. (1)
Uterus – also known as the womb it is where the fertilised zygote will develop. (1)
Oviduct – also known as the fallopian tube it is a tube through which an ovum or egg passes from an ovary. (1)
Ovary – where the unfertilised eggs are stored. (1)
14
Q
Distinguish between and describe sexual and asexual
reproduction.
A
Asexual reproduction does not involve sex cells or fertilisation. Only one parent is required. As a result, the offspring are genetically identical to the parent and to each other. They are clones. (1)
Sexual reproduction allows some of the genetic information from each parent to mix, producing offspring that resemble their parents, but are not identical to them. In this way, sexual reproduction leads to variety in the offspring. Animals and plants can reproduce using sexual reproduction. (1)
15
Q
Define puberty (1)
A
The reproductive system of a child is not mature. It needs to change as a boy or girl develops into an adult, so that the system is fully working. The time when the changes happen is called puberty. (1)
16
Q
Define and describe adolescence. (1)
A
Adolescece is the time between puberty and adulthood. (1)
17
Q
Describe puberty in males. (3)
A
Testicles produce sperm. (1)
Penis grows longer and wider. (1)
Testicles grow larger and fuller. (1)
Wet Dreams. (1)
18
Q
Describe puberty in females. (5)
A
Ovaries start releasing eggs. (1)
Periods start. (1)
Produce vaginal discharge. (1)
Breasts develop. (1)
Hips get bigger. (1)
19
Q
Describe puberty in males and females. (13)
A
Grow taller. (1)
Skin becomes oily. (1)
Spots appear on skin. (1)
Hair grows on face. (1)
Hair grows under arms. (1)
Hair grows on arms and face. (1)
Hair grows on genitals (pubic hair). (1)
Body produces sex hormones. (1)
Weight gain. (1)
Body shape changes. (1)
Face shape changes. (1)
Voice becomes deeper. (1)
Body sweats more. (1)
20
Q
The stages of the menstrual cycle. (1)
A
1 - Bleeding from the vagina begins. This is caused by the loss of the lining of the uterus. This is called menstruation or having a period. (1)
5 - Blood loss stops. The lining of the uterus begins to re-grow and an ovum starts to mature in one of the ovaries. (1)
14 - Ovulation occurs. The ovum travels through the oviduct towards the uterus. (1)
28 - If the ovum does not join with a sperm cell in the oviduct, the lining of the uterus begins to break down again and the cycle repeats. (1)
21
Q
Fertilisation, implantation and development of the
embryo.
A
Fertilisation is the process in which the nucleus of a sperm cell fuses with the nucleus of an egg cell to produce a zygote which will eventually grow into offspring. (1)
When the embryo reaches the uterus , implantation occurs. This is when the embryo attaches to the thick uterus lining to receive nourishment. The placenta , umbilical cord , amnion and amniotic fluid form. (1)
A fertilised ovum divides to form a ball of cells called an embryo. The embryo attaches to the lining of the uterus. It begins to develop into a fetus and then becomes a baby when it is born. It takes about 40 weeks for a fetus to develop in the uterus. This time is called gestation. (1)
22
Q
Function of the placenta and the umbilical cord.
A
The placenta allows substances to diffuse from the mother’s blood to the foetus (e.g. oxygen and glucose).
Substances can also diffuse from the foetus to the mother’s blood (e.g. carbon dioxide and urea).
The umbilical cord attaches the placenta to the foetus. It contains the umbilical artery and the umbilical vein.
The umbilical artery carries urea and carbon dioxide from the foetus to the mother’s blood.
The umbilical vein carries oxygen and nutrients from the mother’s blood to the foetus.
Maternal blood and foetal blood systems are close together but not joined. They are separated by thin membranes that allow diffusion to occur.
23
Q
Pregnancy and Birth.
A
- The muscular uterus walls begin to contract.
- The contractions becomes stronger and the cervix muscle starts to relax.
- At some stage the amnion breaks and the fluid comes out of the vagina.
- Once the cervix is 10cm dilated the strong contractions begin to push the baby out.
- The baby comes out head first, the umbilical cord is tied and cut.
- About half an hour after the baby is born the placenta breaks away and passes out of the vagina.
24
The Circulatory System; describe the role of the veins and arteries, and how blood circulates around the body.
The circulatory system, also known as the cardiovascular system, is a complex network of vessels, including arteries and veins, that facilitates the flow of blood throughout the body. The heart is the central organ that pumps blood, and the blood vessels help distribute oxygen, nutrients, and hormones to cells while removing waste products. The two primary types of blood vessels involved in circulation are arteries and veins.
Arteries:
Role: Arteries carry oxygenated blood away from the heart to various parts of the body. The largest artery is the aorta, which branches into smaller arteries that further divide and supply blood to organs, tissues, and cells.
Characteristics: Arteries have thick, muscular walls to withstand the high pressure generated by the pumping action of the heart. The elastic nature of these walls helps maintain a continuous flow of blood even between heartbeats.
Oxygen Content: In systemic circulation, arteries carry oxygenated blood (except for the pulmonary artery, which carries deoxygenated blood to the lungs for oxygenation).
Veins:
Role: Veins carry deoxygenated blood back to the heart. After blood delivers oxygen and nutrients to tissues, it returns to the heart through veins, ultimately entering the right atrium of the heart.
Characteristics: Veins have thinner walls compared to arteries, as the blood pressure in veins is lower. Veins also have one-way valves that prevent the backflow of blood, helping maintain the flow towards the heart.
Oxygen Content: In systemic circulation, veins carry deoxygenated blood (except for the pulmonary veins, which carry oxygenated blood from the lungs to the left atrium).
Blood Circulation:
Systemic Circulation:
Oxygenated blood is pumped from the left ventricle of the heart into the aorta.
Arteries branch out, delivering oxygenated blood to organs, tissues, and cells throughout the body.
Capillaries, the smallest blood vessels, facilitate the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues.
Deoxygenated blood, now in veins, returns to the heart, entering the right atrium.
Pulmonary Circulation:
Deoxygenated blood from the right atrium is pumped into the pulmonary artery.
The pulmonary artery carries blood to the lungs, where oxygen is picked up, and carbon dioxide is released.
Oxygenated blood returns to the heart through the pulmonary veins, entering the left atrium.
Heartbeat and Coordination:
The heart's contraction (systole) and relaxation (diastole) create a rhythmic cycle that propels blood through the circulatory system.
The sinoatrial (SA) node in the heart initiates the electrical signal that regulates the heartbeat, ensuring coordinated contractions of the atria and ventricles.
25
Describe how an antagonistic pair of muscles cause
movement. (Use the triceps and biceps as your example)
Antagonistic muscle pairs work together to produce controlled and coordinated movements around joints. An antagonistic pair typically consists of two muscles with opposing actions — when one muscle contracts (agonist), the other relaxes (antagonist), and vice versa. This mechanism allows for smooth and precise control of movement. Let's use the example of the triceps and biceps in the arm to illustrate how an antagonistic pair of muscles causes movement.
Triceps and Biceps as Antagonistic Muscles:
Biceps (Agonist):
Location: The biceps brachii is a muscle located on the front of the upper arm.
Action: The primary action of the biceps is to flex the forearm at the elbow joint. When the biceps contracts, it shortens, pulling the forearm towards the upper arm.
Triceps (Antagonist):
Location: The triceps brachii is a muscle located on the back of the upper arm.
Action: The primary action of the triceps is to extend the forearm at the elbow joint. When the triceps contracts, it straightens the arm by pulling the forearm away from the upper arm.
Movement Process:
Flexion (Biceps Action):
When you decide to bend your arm, the biceps act as the agonist.
The biceps contract, shortening and pulling the forearm towards the upper arm.
This results in the flexion of the elbow joint.
Extension (Triceps Action):
When you decide to straighten your arm, the triceps act as the agonist.
The triceps contract, straightening the arm by pulling the forearm away from the upper arm.
This results in the extension of the elbow joint.
Reciprocal Inhibition:
The concept of reciprocal inhibition ensures smooth movement by coordinating the contraction and relaxation of agonist and antagonist muscles.
When the biceps contract to flex the forearm, the triceps undergo reciprocal inhibition, relaxing to allow the movement to occur smoothly.
When the triceps contract to extend the forearm, the biceps undergo reciprocal inhibition, facilitating the extension movement.
This antagonistic muscle pair, involving the biceps and triceps, allows for the controlled and precise movement of the forearm at the elbow joint. Whether you are lifting a weight, reaching for an object, or performing other daily activities, the coordinated action of agonist and antagonist muscles is essential for efficient and purposeful movement around joints.
26
What are joints and how do they aid movement?
Joints, also known as articulations, are points in the body where two or more bones come together. Joints play a crucial role in facilitating movement, providing flexibility, and allowing different parts of the skeleton to work together. There are various types of joints in the human body, each with its own structure and range of motion. The three main types of joints are:
Fibrous Joints:
Structure: These joints are connected by tough, fibrous connective tissue and allow minimal or no movement. The bones in fibrous joints are closely united, providing stability.
Examples: Sutures between the bones of the skull.
Cartilaginous Joints:
Structure: These joints are connected by cartilage, a more flexible and elastic connective tissue compared to fibrous tissue. Cartilaginous joints allow limited movement.
Examples: Intervertebral discs in the spine.
Synovial Joints:
Structure: Synovial joints are the most common type of joint and are characterized by the presence of a synovial cavity, synovial membrane, articular cartilage, and ligaments. These joints allow a wide range of movement.
Examples: Knee joint, hip joint, shoulder joint.
How Joints Aid Movement:
Providing Movement Axis:
Joints serve as pivot points or axes around which bones can move. The type of joint determines the range and direction of movement.
Allowing Flexibility:
The structure of synovial joints, with their synovial fluid-filled cavities and articular cartilage, allows for smooth and flexible movement. The synovial fluid lubricates the joint surfaces, reducing friction during movement.
Permitting Range of Motion:
Different types of joints permit different ranges of motion. For example, ball-and-socket joints (e.g., hip and shoulder joints) allow for a wide range of motion in multiple directions, while hinge joints (e.g., elbow and knee joints) primarily allow flexion and extension.
Providing Stability:
Joints are designed to provide stability to the skeleton. Ligaments, which connect bone to bone, and tendons, which connect muscle to bone, contribute to joint stability.
Absorbing Shock:
Joints, particularly those with cartilage (e.g., synovial joints), help absorb shock and distribute forces during movements like walking, running, or jumping.
Facilitating Specialized Movements:
Some joints are specialized for specific movements. For example, the pivot joint in the neck allows rotation, while the saddle joint in the thumb permits a wide range of movements, including opposition.
Enabling Everyday Activities:
Joints are essential for everyday activities, from simple tasks like bending the elbow to more complex movements like walking or playing sports. The coordinated action of muscles and joints allows for purposeful and controlled movement.
Overall, joints are critical components of the musculoskeletal system, contributing to the body's ability to move, maintain posture, and perform various physical activities. The diversity in joint types and their functions reflects the adaptability and complexity of the human body.
27
How humans move using bones, muscles, tendons and
ligaments
Human movement is a complex process that involves the coordinated action of bones, muscles, tendons, and ligaments. The musculoskeletal system, comprised of these components, works together to produce purposeful and controlled movements. Here's how these elements interact to facilitate movement:
Bones:
Bones provide the structural framework for the body and serve as attachment points for muscles. The skeletal system consists of bones connected at joints, allowing for movement. Different types of joints enable various ranges of motion.
Muscles:
Muscles are responsible for generating force and producing movement. Muscles work in pairs: the agonist (contracting muscle) and the antagonist (opposite muscle that relaxes to allow movement). When one muscle contracts, the other relaxes, facilitating controlled movement.
Types of Muscle Contractions:
Isometric Contraction: Muscles generate force without changing length (e.g., holding a static position).
Concentric Contraction: Muscles shorten as they generate force (e.g., lifting a weight).
Eccentric Contraction: Muscles lengthen while generating force (e.g., lowering a weight).
Muscle Attachments: Muscles are attached to bones by tendons, allowing the transmission of force from muscle to bone.
Tendons:
Tendons are tough, fibrous connective tissues that connect muscles to bones. They transmit the force generated by muscle contractions to the bones, enabling movement. Tendons are essential for stability and efficient transfer of muscle force to the skeletal system.
Ligaments:
Ligaments are strong bands of connective tissue that connect bones to bones, providing stability to joints. Ligaments limit excessive movement and help prevent dislocations. They play a crucial role in supporting joints during dynamic activities.
Process of Movement:
Nervous System Control:
The nervous system plays a key role in controlling movement. The brain sends signals to motor neurons, which activate muscle contractions. Sensory feedback from muscles, tendons, and joints helps regulate the intensity and duration of muscle contractions.
Muscle Contraction:
When a movement is initiated, the agonist muscle contracts, generating force. This contraction results in the shortening of muscle fibers.
Joint Movement:
The force generated by muscle contraction is transmitted to the bones through tendons. As tendons pull on bones, joint movement occurs.
Antagonistic Muscle Action:
While the agonist muscle contracts, the antagonist muscle relaxes to allow the desired movement. This antagonistic action helps control the speed and precision of movement.
Joint Stability:
Ligaments provide stability to the joints, preventing excessive movement and maintaining proper alignment.
Energy Generation:
The energy required for muscle contraction is derived from the breakdown of adenosine triphosphate (ATP). ATP is produced through cellular processes, including aerobic and anaerobic metabolism.
Feedback Mechanisms:
Sensory receptors in muscles, tendons, and joints provide feedback to the nervous system about the position of body parts, muscle tension, and joint angles. This feedback helps adjust muscle contractions to maintain balance and coordination.
Through the intricate interplay of bones, muscles, tendons, and ligaments, the human body is capable of a wide range of movements, from simple tasks like walking to complex activities like playing sports. The coordination of these elements ensures that movements are efficient, purposeful, and adaptable to various environmental conditions.
28
The function of the skeletal system and structure of
bones.
The skeletal system, composed of bones, cartilage, and connective tissues, serves several crucial functions in the human body. The skeletal system provides structural support, protection of vital organs, facilitation of movement, storage of minerals, and blood cell formation. Here's an overview of the functions and structure of bones within the skeletal system:
Functions of the Skeletal System:
Structural Support:
Bones form the framework of the body, providing structural support for muscles, tissues, and organs. The skeleton maintains the body's shape and posture.
Protection:
The skeletal system protects vital organs from mechanical damage. For example, the skull protects the brain, the ribcage shields the heart and lungs, and the vertebrae safeguard the spinal cord.
Facilitation of Movement:
Bones, in conjunction with muscles and joints, allow for a wide range of movements. Muscles contract and pull on bones, producing joint movements that enable activities such as walking, running, and grasping objects.
Storage of Minerals:
Bones serve as a reservoir for essential minerals, particularly calcium and phosphorus. These minerals can be released into the bloodstream when needed for various physiological functions, such as muscle contraction and nerve transmission.
Blood Cell Formation:
Within the bone marrow, a soft tissue found in the cavities of certain bones, blood cells are produced. This process, known as hematopoiesis, involves the formation of red blood cells, white blood cells, and platelets.
Energy Storage:
Yellow bone marrow, found in the central cavities of long bones, serves as a site for fat storage. This fat can be utilized as an energy source during periods of increased energy demand.
Structure of Bones:
Compact Bone:
The outer layer of bones is composed of compact bone, a dense and hard tissue. Compact bone provides strength and protection. It contains osteons, which are cylindrical structures consisting of concentric rings of bone matrix.
Spongy (Cancellous) Bone:
The inner part of many bones contains spongy bone, which has a porous and lattice-like structure. Spongy bone is lighter than compact bone and provides a network for blood vessels and marrow.
Bone Marrow:
Bone marrow is a soft, gelatinous tissue found in the cavities of bones. Red bone marrow is involved in blood cell formation (hematopoiesis), while yellow bone marrow stores fat.
Periosteum:
The periosteum is a thin, fibrous membrane that covers the outer surface of bones. It contains blood vessels, nerves, and cells involved in bone growth and repair.
Articular Cartilage:
At the ends of bones within joints, there is articular cartilage, a smooth and slippery tissue that reduces friction and absorbs shock during joint movement.
Bone Cells:
Osteocytes, osteoblasts, and osteoclasts are the main types of bone cells. Osteocytes are mature bone cells embedded in the bone matrix, osteoblasts are responsible for bone formation, and osteoclasts are involved in bone resorption or breakdown.
Haversian Canals:
Haversian canals are channels within compact bone that contain blood vessels and nerves. They provide nutrients and oxygen to bone cells.
The combination of these structural components contributes to the strength, flexibility, and adaptability of bones. The dynamic nature of bone tissue allows for continuous remodeling in response to mechanical stress, injury, and changes in mineral homeostasis. This ability to adapt is essential for maintaining the integrity and functionality of the skeletal system throughout life.
29
How are the villi in the small intestine adapted to their
function.
The small intestine is a crucial organ in the digestive system responsible for the absorption of nutrients from digested food. The surface of the small intestine is lined with finger-like projections called villi, and these structures are highly adapted to enhance the efficiency of nutrient absorption. The adaptations of villi include:
Increased Surface Area:
Villi significantly increase the surface area available for nutrient absorption. The numerous, finger-like projections extend into the lumen of the small intestine, creating a large surface area for the absorption of nutrients. This increased surface area allows for more efficient absorption of nutrients such as carbohydrates, proteins, fats, and vitamins.
Microvilli on Villi's Surface:
Each villus is covered with even smaller projections called microvilli, forming a brush border on the surface. Microvilli further amplify the surface area for absorption. The extensive microvilli greatly enhance the absorption of nutrients by providing additional sites for nutrient uptake.
Rich Blood Supply:
Each villus contains a network of blood capillaries and a lacteal (a lymphatic vessel). The dense network of blood vessels ensures that absorbed nutrients are quickly transported away from the small intestine to other parts of the body for utilization. The lacteal is involved in the absorption of dietary fats and fat-soluble vitamins.
Thin Epithelial Layer:
The epithelial layer covering the villi is very thin, allowing for efficient diffusion of nutrients. The thinness of the epithelium facilitates the rapid movement of absorbed substances from the lumen of the small intestine into the bloodstream or lymphatic system.
Presence of Absorptive Cells:
The epithelial layer on the surface of villi contains specialized absorptive cells (enterocytes) with microvilli. These cells are equipped with transport proteins that facilitate the uptake of nutrients into the bloodstream.
Secretory Cells:
Among the cells on the villi are goblet cells, which secrete mucus. Mucus helps protect the lining of the small intestine, lubricates the passage of food, and creates a favorable environment for nutrient absorption.
Rapid Cell Renewal:
The cells on the surface of the villi have a high rate of turnover and are constantly being renewed. This rapid cell renewal ensures that the absorptive surface remains functional and efficient in nutrient absorption.
Presence of Enzymes:
Enzymes embedded in the surface of the villi help break down complex nutrients into simpler, absorbable forms. These enzymes contribute to the digestion and absorption of carbohydrates, proteins, and fats.
The adaptations of villi in the small intestine collectively optimize the absorption of nutrients from the digested food, ensuring that essential substances are efficiently taken up by the body for energy production, growth, and maintenance of overall health.
30
What is peristalsis and how does fibre affect it?
Peristalsis:
Peristalsis is a coordinated and rhythmic muscular contraction and relaxation of the muscles in the walls of the digestive tract, primarily the esophagus, stomach, small intestine, and large intestine. This process helps move food through the digestive system, allowing for the mechanical breakdown and absorption of nutrients. Peristalsis is an involuntary and automatic process regulated by the enteric nervous system, which is sometimes referred to as the "second brain" of the digestive system.
Role of Peristalsis:
Esophagus: Peristalsis helps propel food from the mouth to the stomach through the esophagus.
Stomach: In the stomach, peristaltic waves mix and churn food with digestive juices, forming a semi-liquid substance known as chyme.
Small Intestine: Peristalsis in the small intestine facilitates the movement of chyme and promotes the absorption of nutrients.
Large Intestine: Peristaltic contractions in the large intestine assist in moving undigested material toward the rectum for elimination.
Role of Fiber in Peristalsis:
Dietary fiber, also known as roughage or bulk, consists of indigestible plant material that remains relatively unchanged as it passes through the digestive system. Fiber plays a significant role in promoting healthy digestion and influencing peristalsis in the following ways:
Increased Bulk:
Fiber adds bulk to the stool. When mixed with water, fiber forms a gel-like substance that increases the volume and softness of the stool. This increased bulk stimulates peristaltic contractions and promotes the efficient movement of stool through the intestines.
Prevention of Constipation:
Insoluble fiber, in particular, helps prevent constipation by promoting regular bowel movements. It does so by speeding up the transit time of stool through the intestines and adding bulk to the feces.
Fermentation and Gas Production:
Certain types of soluble fiber are fermented by bacteria in the colon, producing short-chain fatty acids and gases. This fermentation process stimulates colonic contractions, contributing to the overall motility of the digestive tract.
Regulation of Water Content:
Soluble fiber has the ability to absorb water and form a gel. This gel-like substance can slow down the digestion and absorption of nutrients, promoting a gradual release of nutrients into the bloodstream. Additionally, it helps regulate water content in the intestines, maintaining optimal hydration for peristalsis.
Promotion of a Healthy Microbiota:
Fiber serves as a prebiotic, promoting the growth and activity of beneficial bacteria in the colon. A healthy gut microbiota is associated with improved digestive function and may influence peristalsis indirectly.
It's important to note that a well-balanced diet that includes an adequate amount of both soluble and insoluble fiber is beneficial for digestive health. While soluble fiber is found in foods like oats, beans, and fruits, insoluble fiber is present in whole grains, vegetables, and nuts. Adequate hydration is also essential for the optimal functioning of fiber in promoting healthy digestion and peristalsis.
31
Different teeth types and their function. How to care for
your teeth.
Different Types of Teeth and Their Functions:
Incisors:
Location: Located at the front of the mouth.
Function: Designed for cutting and slicing food. There are four upper and four lower incisors.
Canines (Cuspids):
Location: Pointed teeth next to the incisors.
Function: Used for tearing and gripping food. There are two upper and two lower canines.
Premolars (Bicuspids):
Location: Located behind the canines.
Function: Have flat surfaces with ridges and are used for grinding and tearing food. There are four upper and four lower premolars.
Molars:
Location: Located at the back of the mouth.
Function: Broad, flat surfaces for grinding and crushing food. There are six upper and six lower molars.
Wisdom Teeth (Third Molars):
Location: The third set of molars at the back of the mouth.
Function: Historically used for grinding plant tissues, but many people have them removed due to limited space in the jaw and potential issues.
How to Care for Your Teeth:
Regular Brushing:
Brush your teeth at least twice a day using fluoride toothpaste. Use a soft-bristled toothbrush and brush for at least two minutes. Pay attention to all surfaces of the teeth, including the chewing surfaces, outer surfaces, and inner surfaces.
Flossing:
Floss daily to remove plaque and food particles from between your teeth and below the gumline. This helps prevent cavities and gum disease.
Use Mouthwash:
Rinse with an antimicrobial or fluoride mouthwash to help reduce plaque, fight bacteria, and strengthen teeth. Choose a mouthwash without alcohol if you have dry mouth concerns.
Maintain a Balanced Diet:
Eat a well-balanced diet rich in fruits, vegetables, whole grains, lean proteins, and low-fat dairy. Limit sugary snacks and beverages, as they contribute to tooth decay.
Limit Acidic Foods and Drinks:
Acidic foods and drinks can erode tooth enamel. Limit the consumption of acidic items such as citrus fruits, sodas, and acidic candies.
Drink Water:
Drink plenty of water throughout the day, especially after meals. Water helps rinse away food particles and bacteria and contributes to overall oral health.
Regular Dental Check-ups:
Schedule regular dental check-ups and cleanings with your dentist. Professional cleanings remove plaque and tartar that regular brushing and flossing may miss.
Use Fluoride:
Ensure you have an adequate intake of fluoride, whether through fluoridated water, toothpaste, or fluoride treatments recommended by your dentist. Fluoride helps strengthen tooth enamel and prevent cavities.
Protect Teeth During Sports:
Wear a mouthguard when participating in contact sports or activities with a risk of injury to the mouth. This helps prevent dental injuries.
Avoid Smoking and Tobacco Products:
Smoking and tobacco use contribute to gum disease, tooth decay, and other oral health issues. Quitting or avoiding these habits is essential for overall oral and systemic health.
By incorporating these practices into your daily routine, you can maintain good oral hygiene, prevent dental problems, and contribute to the overall health of your teeth and gums. Regular dental care and healthy habits play a crucial role in preserving your smile and preventing oral health issues.
32
List and explain the stages of digestion; ingestion
digestion, absorption, assimilation and egestion,
The process of digestion involves the mechanical and chemical breakdown of food into smaller, absorbable components that can be utilized by the body. The stages of digestion can be summarized as follows:
Ingestion:
Definition: Ingestion is the process of taking food into the mouth.
Function: It marks the beginning of the digestive process, where food is introduced into the digestive system. During ingestion, food is broken down into smaller particles by chewing and mixed with saliva to form a bolus.
Digestion:
Mechanical Digestion:
Definition: Mechanical digestion involves the physical breakdown of food into smaller particles.
Function: Chewing in the mouth (mastication) and the churning action of the stomach are examples of mechanical digestion. These processes increase the surface area of food, making it easier for enzymes to act on it.
Chemical Digestion:
Definition: Chemical digestion involves the breakdown of complex food molecules into simpler substances through the action of enzymes.
Function: Enzymes in saliva (amylase), stomach (pepsin), and various parts of the small intestine (pancreatic enzymes) break down carbohydrates, proteins, and fats into their respective building blocks—sugars, amino acids, and fatty acids.
Absorption:
Definition: Absorption is the process by which the products of digestion (nutrients) are absorbed into the bloodstream or lymphatic system.
Function: Small intestine villi and microvilli greatly increase the surface area for absorption. Nutrients, such as glucose, amino acids, and fatty acids, are transported across the intestinal lining and into the blood or lymph, where they can be distributed to cells throughout the body.
Assimilation:
Definition: Assimilation is the process by which absorbed nutrients are used by cells for growth, energy, and maintenance.
Function: Once absorbed, nutrients are transported to various cells and tissues in the body, where they are used to build and repair tissues, produce energy (as in cellular respiration), and carry out other physiological functions.
Egestion (Elimination):
Definition: Egestion, also known as elimination, is the removal of undigested and unabsorbed materials from the body.
Function: Indigestible substances, along with some water, are formed into feces in the large intestine. Fecal matter is then expelled from the body through the rectum and anus during the process of defecation.
These stages of digestion collectively allow the body to break down ingested food into its essential components, absorb nutrients, utilize those nutrients for various bodily functions, and eliminate waste. The digestive system plays a crucial role in maintaining the body's energy balance, supporting growth and development, and ensuring the proper functioning of various physiological processes.
33
Distinguish between physical and chemical digestion.
Define and enzyme.
Physical Digestion vs. Chemical Digestion:
Physical Digestion:
Definition: Physical digestion involves the mechanical breakdown of food into smaller particles without changing the chemical composition.
Mechanisms: Chewing in the mouth (mastication), churning action in the stomach, and segmentation in the small intestine are examples of physical digestion. These processes increase the surface area of food, making it easier for enzymes to act on it during chemical digestion.
Purpose: Physical digestion facilitates the exposure of a larger surface area of food to digestive enzymes, enhancing the efficiency of chemical digestion.
Chemical Digestion:
Definition: Chemical digestion involves the breakdown of complex food molecules into simpler substances through the action of enzymes and other digestive chemicals.
Mechanisms: Enzymes in saliva (amylase), stomach (pepsin), and various parts of the small intestine (pancreatic enzymes) break down carbohydrates, proteins, and fats into their respective building blocks—sugars, amino acids, and fatty acids.
Purpose: Chemical digestion breaks down food into forms that can be absorbed and utilized by the body during absorption and assimilation.
Enzyme:
Definition: An enzyme is a biological molecule (typically a protein) that acts as a catalyst to facilitate and accelerate chemical reactions within living organisms.
Function: Enzymes are essential for various physiological processes, including digestion. They facilitate the breakdown of complex molecules into simpler substances without being consumed in the process.
Specificity: Enzymes are highly specific, each designed to catalyze a particular type of chemical reaction. For example, amylase breaks down carbohydrates, pepsin breaks down proteins, and lipase breaks down fats.
Activation: Enzymes lower the activation energy required for a chemical reaction to occur, making the reaction more efficient and allowing it to proceed at physiological temperatures and conditions.
Substrate: The molecule on which an enzyme acts is called the substrate. Enzymes bind to the substrate at their active sites, where the catalytic reaction takes place.
Regulation: Enzyme activity can be regulated by factors such as temperature, pH, and the presence of specific cofactors or inhibitors.
In the context of digestion, enzymes play a crucial role in breaking down complex food molecules into smaller, absorbable forms. Each enzyme is specific to its substrate, ensuring that the digestive process is finely tuned and targeted to the types of nutrients present in the ingested food.
34
The Digestive System, draw, label and describe the main
parts and the function of each part.
1. Mouth:
Function: Ingestion and the beginning of mechanical digestion. Chewing (mastication) breaks down food into smaller particles, and salivary enzymes (amylase) initiate the chemical digestion of carbohydrates.
2. Esophagus:
Function: The esophagus is a muscular tube that transports chewed food (bolus) from the mouth to the stomach through a series of coordinated muscle contractions known as peristalsis.
3. Stomach:
Function: Mechanical and chemical digestion. The stomach churns and mixes food with gastric juices containing hydrochloric acid and pepsin, initiating the breakdown of proteins. The result is a semi-liquid mixture called chyme.
4. Small Intestine:
Function: Most of digestion and nutrient absorption occur in the small intestine. It consists of three parts: duodenum, jejunum, and ileum.
Duodenum: Receives chyme from the stomach and mixes it with digestive enzymes from the pancreas and bile from the liver to break down carbohydrates, proteins, and fats.
Jejunum and Ileum: Primary sites for nutrient absorption. Villi and microvilli on the intestinal lining increase the surface area for absorption.
5. Pancreas:
Function: Produces digestive enzymes (pancreatic amylase, lipase, and protease) that are released into the duodenum to further break down carbohydrates, fats, and proteins.
6. Liver:
Function: Produces bile, which is stored in the gallbladder. Bile emulsifies fats, breaking them into smaller droplets to facilitate enzymatic digestion.
7. Gallbladder:
Function: Stores and releases bile into the duodenum to aid in the digestion and absorption of fats.
8. Large Intestine (Colon):
Function: Absorption of water and electrolytes, as well as the formation and storage of feces. The colon also houses beneficial bacteria that contribute to the fermentation of undigested carbohydrates and the production of certain vitamins.
9. Rectum:
Function: The rectum stores feces until they are ready to be eliminated from the body.
10. Anus:
Function: The anus is the opening through which feces are expelled from the body during the process of defecation.
Understanding the functions of each part of the digestive system provides insight into how the body processes food, extracts nutrients, and eliminates waste. You can use this information to label the respective parts on a diagram to create a comprehensive representation of the digestive system.
35
What 3 factors are required for germination? Understand the difference between a shoot and a root. (5)
Moisture (1)
Warmth (1)
Oxygen (1)
The main difference between a shoot and a root is that shoots are parts of the plant that grow above the ground, (1) whereas roots are parts of the plant that grow below the ground. (1)
36
Be able to describe the stages of germination. (5)
Step 1: Imbibition: water fills the seed. (1)
Step 2: The water activates enzymes that begin the plant's growth. (1)
Step 3: The seed grows a root to access water underground. (1)
Step 4: The seed grows shoots that grow towards the sun. (1)
Step 5: The shoots grow leaves and begin photmorphogenesis. (1)
37
The male and female parts of the plant and their
function, be able to draw and label a flower including their parts. (5)
Male Parts of Plant (Stamen):
Anther - produces male sex cells (contained in the pollen grain) (1)
Filament - holds up the anther. (1)
Female Parts of Plant (Carpel):
Stigma - traps pollen (1)
Style - where pollen tube grows down to female sex cells. (1)
Ovary produces - female sex cells ( contained in the ovules) (1)
PPT 38
38
Define and describe the stages of Pollination. (6)
Pollination is the transfer of pollen grains from an anther to a stigma. Pollen can be transferred by an animal or by the wind. (1)
Fertilisation takes place inside the ovary when the nucleus of pollen grain fuses with the nucleus of an ovule to produce a zygote. (1)
A seed is a mature fertilised ovule of a plant. Seed formation is when a seed is formed. (1)
Step one: After pollen has landed on the stigma, it grows a pollen tube down through the style to the ovary. (1)
Step two: The nucleus of the pollen grain travels down the pollen tube and fertilises the nucleus in the ovule. (1)
Step three: The fertilised ovule develops into a seed. The seed contains the plant embryo, which contains genetic material from both parents. The ovary develops into the fruit. (1)
39
Describe the various methods of seed dispersal. (5)
Seed dispersal is the transport of seeds from the plant to another area in order to grow. (1)
These are the main ways in which seeds can be dispersed:
Animals (1)
Explosion (1)
Wind (1)
Water (1)
40
Define photosynthesis and write a full word equation for the reaction. List the reactants and products. (3)
Carbon dioxide + Water →(sunlight)→ Glucose + Oxygen (1)
CO2 +H20 = Reactants (1)
C₆H₁₂O₆ + O2 = Products (1)
41
What is chlorophyll, where is it found and what is its role in photosynthesis?
Chlorophyll is a green chemical (1) found within chloroplasts in cells exposed to light. (1)
It absorbs the light energy required to convert carbon dioxide and water into glucose. (1)
42
What is the role of light in the photosynthesis reaction?
Light energy absorbed by chlorophyll is converted into chemical energy. (1)
43
Where does Photosynthesis take place, which cell
organelle and which part of the plant.
Photosynthesis takes place in chloroplast, which is located mainly at the top of a leaf, where it receives the most light energy possible. (1)
44
Draw and label a leaf. State how the leaf is adapted to its function.
Leaves are adapted for photosynthesis and gaseous exchange. They are adapted for photosynthesis by having a large surface area, and contain openings, called stomata to allow carbon dioxide into the leaf and oxygen out. (1)
45
Test the leaf for Starch
Prepare the sample: Take a small amount of the substance you want to test for starch. This could be a food item, plant material, or any other material suspected to contain starch.
Apply iodine solution: Place a few drops of iodine solution onto the sample. Iodine solution is typically made by dissolving iodine crystals in potassium iodide solution. It's commonly available in chemistry laboratories and can also be purchased from chemical suppliers.
Observe the color change: If starch is present in the sample, the iodine solution will undergo a color change. The solution will turn from its original reddish-brown color to a dark blue or black color. This color change occurs due to the formation of a starch-iodine complex, which has a blue-black color.
46
State the Limiting Factors of Photosynthesis
Light Intensity
Carbon Dioxide (CO2) Concentration
Temperature
Water Availability
Chlorophyll Content
Nutrient Availability
Oxygen Concentration
47
Describe an Experiment to show the effect of Light Intensity on the rate of photosynthesis
To demonstrate the effect of light intensity on the rate of photosynthesis, set up a series of plant samples, such as Elodea or spinach leaves, in separate containers filled with a standardized solution of water and bicarbonate ions to ensure a constant supply of carbon dioxide. Place each container at different distances from a light source to create varying light intensities. Use a timer to measure the production of oxygen bubbles or the uptake of carbon dioxide over a set period under each light condition. By comparing the rates of photosynthesis at different light intensities, a relationship between light intensity and the rate of photosynthesis can be observed, typically showing an increase in photosynthesis rate with higher light intensity up to a certain point, beyond which the rate plateaus due to other limiting factors.
48
Draw and Label the male/female parts of a plant
Male Parts (Stamen):
Anther:
Located at the top of the stamen.
Contains pollen sacs where pollen (male gametes) is produced.
Filament:
A slender stalk that supports the anther, positioning it for optimal pollen dispersal.
Female Parts (Pistil or Carpel):
Stigma:
Located at the top of the pistil.
Sticky surface that captures pollen.
Style:
A tube-like structure that connects the stigma to the ovary.
Ovary:
Enlarged basal part of the pistil.
Contains ovules, each housing an egg cell (female gamete).
49
What minerals are needed for plant growth and how they enter the plant
Plants require several essential minerals for growth, including nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, zinc, copper, boron, and molybdenum. These minerals are absorbed by the plant roots from the soil solution in the form of ions. The process involves active transport and passive diffusion mechanisms, depending on the concentration gradient and the specific properties of each mineral. Once absorbed, these minerals play critical roles in various biochemical processes within the plant, such as photosynthesis, cell structure, enzyme activation, and nutrient storage.
50
Define the main key terms; ecology, habitat, population,
community, ecosystem.
Ecology is the study of the interaction between organisms and their environment. (1)
Habitat - the place where an organism lives. (1)
Population - all the members of a single species that live in a habitat. (1)
Community - all the populations of different organisms that live together in a habitat. (1)
An ecosystem is a community of animals, plants, micro-organisms, non-living things and their shared environment. (1)
51
What are the factors that affect an environment? (11)
Abiotic Factors: (1)
Light intensity. (1)
Temperature. (1)
Soil pH. (1)
Soil moisture. (1)
Biotic factors: (1)
Food availability. (1)
Competition for environmental resources. (1)
Grazing. (1)
Predation. (1)
Disease.(1)
52
The role of decomposers in a food chain. (1)
Decomposers are bacteria and fungi that break down dead plant and animal matter. (1)
53
Does all energy in a food chain comes from the sun but does only 10% of energy is passed on to each level of the food chain? (1)
Yes (1)
54
Do green plants get their energy from photosynthesis and animals get their energy from respiration? (1)
Yes (1)
55
Feeding relationships, food chains and webs. Name the
organisms at all trophic levels. (4)
Feeding relationships show what organisms eat or are eaten by others and through this the levels of organisation in an ecosystem. (1)
A food chain is a list of organisms in a habitat that shows their feeding relationship, i.e what eats what. (1)
A food web. is a network of interconnected food chains . It shows the energy flow through part of an ecosystem. (1)
Producer, Primary Consumer, Secondary Consumer, Tertiary Consumer. (1)
56
Factors limiting population growth; list and describe the
four factors.
Food, Water, Living Space, and Disease. (1)
Anything sensible for Part 2. (1)
57
What causes changes in populations sizes? (1)
Birth, Death, Immigration, Emmigration (1)
58
How organisms, both plants and animals, adapt to their
environment. Give an example of an organism and how it has adapted to its environment.
Adaptations are traits that help an organism survive in its environment. (1)
Animals have a wide range of structural adaptations including sharp claws to catch prey , dig burrows or scratch trees to signal territories. (1)
59
Aerobic Respiration
Anaerobic Respiration
Glucose + oxygen -> carbon dioxide+ water
Glucose -> Lactic Acid
60
How to test for the products of respiration
Carbon Dioxide makes limewater cloudy, water turns anhydrous copper sulphate blue.
61
Define a Drug
A drug is any chemical that alters the activities of the body.
62
Define a depressant and a stimulating and give examples
of both.
Depressent - a drug reducing functional or nervous activity (Alcohol, Benzodiazepines, GHB, Kava)
Stimulant - a substance that raises levels of physiological or nervous activity in the body (caffeine, nicotine, amphetamines and cocaine)
63
List the negative impacts of smoking on the body from
Nicotine, Tar, and Carbon monoxide.
Nicotine An addictive drug that narrows blood vessels and can lead to a heart attack.
Tar A black sticky chemical that can cause cancer.
Carbon monoxide A toxic gas that prevents red blood cells from carrying oxygen.
64
The importance of a balanced diet and regular exercise
for a healthy life style.
It's important to eat a varied and balanced diet to stay healthy. You need to drink plenty of water and eat at least five portions of fruit and vegetables every day. You also need to make sure you exercise regularly to keep your heart, lungs and muscles strong and healthy.
65
What is a microbe and give examples of microbes?
What Are Microbes? Microbes are organisms that are too small to be seen without using a microscope, so they include things like bacteria, archaea, and single cell eukaryotes — cells that have a nucleus, like an amoeba or a paramecium.
66
Describe the properties of viruses and give examples of
common viruses?
Viruses have a very simple form; a DNA or RNA genome - genetic code - surrounded by a protective protein coat. Some viruses, like coronaviruses, have an extra fatty envelope to keep their genetic material safe. This is vital because like all living creatures, viruses aim to pass on their genes by reproducing.
67
Describe the properties of bacteria and how they can be
killed using antibiotics, antiseptics, and disinfectants.
Bacteria are single-celled microorganisms that can vary widely in shape, size, and structure.
Antibiotics target specific bacterial structures or processes, such as cell wall synthesis or protein production, to inhibit bacterial growth or kill bacteria. Antiseptics are antimicrobial substances applied to living tissue to prevent infection by killing or inhibiting the growth of bacteria.
Disinfectants are similar to antiseptics but are used on inanimate objects or surfaces to eliminate or reduce the number of bacteria present.
68
Natural defences – list some barriers to microbes
entering the body.
Physical barriers: The skin serves as a physical barrier that prevents microbes from entering the body. Mucous membranes lining the respiratory, digestive, and reproductive tracts also act as physical barriers.
Chemical barriers: Various substances produced by the body, such as stomach acid, enzymes in tears and saliva, and antimicrobial peptides, create an inhospitable environment for microbes.
69
Natural defences – the role of white blood cells,
phagocytes, and lymphocytes
White blood cells, or leukocytes, are crucial for immunity. Phagocytes engulf and digest foreign particles, while lymphocytes coordinate immune responses.
70
Natural defences - the role of platelets in keeping us
healthy.
Platelets prevent excessive bleeding by forming blood clots when blood vessels are damaged, ensuring vascular integrity and supporting overall health.
71
List some human actions to keep healthy: Personal
hygiene, community actions and provisional of medical
care
Personal Hygiene: Regular handwashing, maintaining oral hygiene, bathing, and practicing safe food handling to prevent the spread of infections.
Community Actions: Vaccination programs, sanitation measures, clean water provision, waste management, and public health education to promote disease prevention and community health.
Provision of Medical Care: Access to healthcare services, including preventive care, diagnosis, treatment, and management of illnesses, along with health screenings and promoting healthy lifestyle choices.
72
Define classification and be able to use a simple
classification key.
Classification, in biology, the establishment of a hierarchical system of categories on the basis of presumed natural relationships among organisms.
73
List the five kingdoms of life and be able to compare and
contrast between the kingdoms.
animal, plant, fungi, protist and monera
74
Distinguish between vertebrate and invertebrates and
give examples of both.
Vertebrates have a backbone, while invertebrates don't. Examples of vertebrates include mammals (like humans), birds, reptiles, amphibians, and fish. Examples of invertebrates include insects (like ants and butterflies), mollusks (like snails and octopuses), annelids (like earthworms), and cnidarians (like jellyfish).
75
Describe the properties of the Phylum Arthapoda
Arthropods have jointed legs, segmented bodies, and an exoskeleton made of chitin. They display bilateral symmetry, undergo molting, and possess well-developed sensory organs. Examples include insects, arachnids, crustaceans, and myriapods.
76
Distinguish between insects and spiders.
Insects have six legs, three body segments (head, thorax, abdomen), and typically wings. Spiders have eight legs, two body segments (cephalothorax, abdomen), and produce silk.
77
List and describe the properties of the five main groups
of vertebrates; fish, amphibians, reptiles, birds, and
mammals
Fish: Aquatic vertebrates with gills for respiration, scales covering their bodies, and typically fins for locomotion.
Amphibians: Vertebrates that start their lives in water with gills, then develop lungs for breathing on land. They have moist skin and undergo metamorphosis.
Reptiles: Vertebrates with scaly skin, usually laying eggs with leathery shells. They are cold-blooded and breathe air through lungs.
Birds: Warm-blooded vertebrates with feathers, beaks, and wings. They lay hard-shelled eggs and have a high metabolic rate, typically capable of flight.
Mammals: Warm-blooded vertebrates with hair or fur, mammary glands for milk production, and typically give birth to live young. They breathe air using lungs and regulate body temperature internally.
78
Distinguish between cold and warm blooded animals.
Cold-blooded animals have body temperatures that fluctuate with their environment, while warm-blooded animals maintain a relatively constant internal temperature, regardless of the external environment.
79
Define variation and describe common variations
between individuals
Variation refers to differences among individuals within a species. Common variations include differences in physical traits (such as size, color, and shape), genetic makeup, behavior, and physiological characteristics.
80
Distinguish between continuous and discontinuous
variation and give examples of both.
Continuous variation involves a range of values for a trait within a population, with no distinct categories. Examples include height in humans or beak length in birds. Discontinuous variation involves distinct categories or classes for a trait, with little or no variation within each category. Examples include blood types in humans or flower color in certain plants.
81
Genes are inherited from parent and they control traits
or characteristics in individuals. True or False?
True
