Specialised Cells and Stem Cells Flashcards

1
Q

Outline the levels of organisation of a multicellular organism (in order). (F)

A
  • specialised cells
  • tissues
  • organs
  • organ systems
  • organism
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2
Q

Define the term “specialised”. (F)

A

Having particular structure to serve a specific function.

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3
Q

Define the term “differentiation”. (F)

A

The process of a cell becoming differentiated. Involves the selective expression of genes in a cell’s genome.

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4
Q

Define the term “cell”. (F)

A

The basic unit of life.

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5
Q

Define the term “tissue”. (F)

A

A collection of specialised cells that perform a particular function or functions.

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6
Q

Define the term “organ”. (F)

A

A collection of tissues that perform a particular function in an organism.

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7
Q

Define the term “organ system”. (F)

A

A collection of organs that perform a particular function in an organism.

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8
Q

Explain why multicellular organisms have specialised cells.

A
  • can divide labour between cells

- more efficient overall

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9
Q

Describe the structure of erythrocytes and link to their function. (F)

A

Transport oxygen around the body.

  • flattened biconcave shape to increase SA:V: can carry more haemoglobin
  • lack nuclei and many other organelles: more space for haemoglobin
  • flexible: can squeeze through capillaries
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10
Q

Describe the structure of neutrophils and link to their function. (F)

A

Essential in immune system.

  • multi-lobed nucleus: easier to squeeze through gaps to access site of infection
  • granular cytoplasm contains many lysosomes: contain enzymes that attack pathogens
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11
Q

Describe the structure of sperm cells and link to their function. (F)

A

Deliver genetic information to the female gamete.

  • tail/flagellum: capable of movement
  • many mitochondria: energy for swimming
  • acrosome on head contains digestive enzymes: digest protective layers on egg for penetration and fertilisation
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12
Q

Describe the structure of palisade cells and link to their function. (F)

A

Absorb light for photosynthesis.

  • many chloroplasts: absorb lots of light
  • rectangular box shape: closely packed to form a continuous layer
  • thin cell walls: increase rate of diffusion of carbon dioxide
  • large vacuole: maintain turgor pressure to keep its shape
  • mobile chloroplasts: can absorb more light
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13
Q

Describe the structure of root hair cells and link to their function. (F)

A

Absorb mineral ions and water from soil.

  • root hair extensions: increase SA of cell to maximise water and mineral ion uptake from soil
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14
Q

Describe the structure of guard cells and link to their function. (F)

A

Allow entry of carbon dioxide for photosynthesis.

  • change shape when they lose water because of osmotic forces: close stoma to prevent further water loss
  • cell wall is thicker on one side: bend outwards to open stomata
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15
Q

State the 4 main categories of tissues in animals.

A
  • nervous
  • epithelial
  • muscle
  • connective
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16
Q

State the adaptation of nervous tissue.

A

Support the transmission of electrical impulses.

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17
Q

State the adaptation of epithelial tissue.

A

Cover body surfaces (internal and external)

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18
Q

State the adaptation of muscle tissue.

A

Contract

19
Q

State the adaptation of connective tissue.

A
  • hold other tissues together

- transport medium

20
Q

Describe the structure of squamous epithelium and link to its function. (F)

A

Present when rapid diffusion across a surface is essential i.e. lining of the lungs.

  • very thin due to flat cells: rapid diffusion
  • one cell thick: rapid diffusion
21
Q

Describe the structure of ciliated epithelium and link to its function. (F)

A

Removes unwanted particles.

  • cilia on surface that move in a rhythmic manner: beat unwanted particles away from important areas
  • goblet cells release mucus: trap unwanted particles and is swept away by cilia
22
Q

Describe the structure of cartilage and link to its function. (F)

A

Prevents the ends of bones rubbing together and causing damage i.e. in between bones.

  • fibres of elastin and collagen: firm and flexible
  • chondrocyte cells embedded in an extracellular matrix:
23
Q

Describe the structure of muscle and link to its function. (F)

A

Needs to contract in order to move bones and different parts of the body.

i. e. Skeletal Muscle
- myofibrils with contractile proteins: can contract

24
Q

State the 2 main categories of tissues in plants.

A
  • epidermis

- vascular

25
Q

State the adaptation of epidermis tissue.

A

To cover plant surfaces.

26
Q

State the adaptation of vascular tissue.

A

Transport of water and nutrients.

27
Q

Describe the structure of the plant epidermis and link to its function. (F)

A

Protects the plant.

  • closely packed cells: prevent pathogen entry
  • waxy, waterproof cuticle: reduce water loss
  • stomata that can open and close: allow carbon dioxide, water vapour and oxygen to enter and exit the plant.
28
Q

Describe the structure of the xylem tissue and link to its function. (F)

A

Transport of water and minerals throughout plants.

  • parenchyma cells
  • xylem vessel
  • pits: water entry and exit
  • strengthened with lignin: provide structural support for plats
29
Q

Describe the structure of the phloem tissue and link to its function. (F)

A

Transport of organic nutrients from leaves and stems to areas of plant that require it.

  • sieve tube cells: allow movement of nutrients
  • companion cells: keep sieve tube elements alive
  • sieve plates: allow movement of nutrients
30
Q

State an example of an organ from an animal and outline its function and structure.

A
  • heart
  • pumps blood around the body
  • muscle and connective tissue
31
Q

State an example of an organ from a plant and outline its function and structure.

A
  • leaf
  • photosynthesis
  • epidermal and vascular tissue
32
Q

Describe the function of the digestive system.

A
  • takes in food
  • breaks down large insoluble molecules into small soluble molecules
  • retains water
  • removes undigested material
33
Q

Describe the function of the cardiovascular system.

A
  • moves blood around the body

- transport system for substances in blood

34
Q

Describe the function of the gaseous exchange system.

A
  • brings air into body
  • oxygen extraction for respiration
  • carbon dioxide removal
35
Q

State 3 examples of organ systems in animals.

A
  • digestive
  • cardiovascular
  • gaseous exchange
36
Q

Define the term “stem cell”. (F)

A

Undifferentiated cells with the potential to differentiate into a variety of the specialised cell types of the organism.

37
Q

Define the term “undifferentiated”. (F)

A

An unspecialised cell originating from mitosis or meiosis.

38
Q

Define the term “totipotent”. (F)

A

A stem cell that can differentiate into any type of cell and form a whole organism.

39
Q

Define the term “pluripotent”. (F)

A

A stem cell that can differentiate into any type of cell, but not form a whole organism.

40
Q

Define the term “multipotent”.(F)

A

A stem cell that can only differentiate into a range of cell types within a certain type of tissue.

41
Q

Define the term “embryonic stem cell”. (F)

A

A stem cell found in an embryo. When it is a zygote, it is totipotent. When a blastocyst is formed (8 cells), it is pluripotent.

42
Q

Define the term “tissue (or adult) stem cell”. (F)

A

A stem cell found after birth, which is multipotent but may be artificially triggered to become pluripotent.

43
Q

Describe the characteristic abilities of stem cells as compared to specialised cells.

A
  • can differentiate into any type of cell

- unspecialised