3a Reproduction

Question 1

What is sexual reproduction?

Answer 1

• Usually 2 parents gametes are involved
• Get some variations
• Is the production of new individuals by fusion of male and female gametes

Question 2

What is asexual reproduction?

Answer 2

• No gametes involved
• No sex cells involved
• Only one parent
• Cloning
• The production of new individuals without fertilisation from division of body cells in the parent

Question 3

Sexual reproduction (summer)

Answer 3

• Involves the joining (fusion) of male and female gametes (sex cells)
• Genes from two parents
• Offspring show variation
• Relatively slow process as a mate has to be found

Question 4

Asexual reproduction (summery)

Answer 4

• No fusion of gametes (sex cells)
• Genes from only one parent
• Offspring show NO variation
• Genetically identical offspring (clones)

Question 5

What are some examples of asexual reproduction?

Answer 5

• Binary fission in bacteria
• Taking plant cuttings
• Cloning
• Runners in plants eg. strawberry plants
  Some of these methods of asexual reproduction are natural and some are artificial. All offspring from asexual reproduction are clones of the parent. They have identical DNA to the parent

Question 6

How do you clone a plant?

Answer 6

Taking Cuttings
- Whenever you “clip” off a piece of a plant and put it to grow in new soil you are making a clone of the plant
- The new plant is identical to the plant that you took the clipping from
- This is because plants grow by asexual reproduction

Question 7

What are gametes and where are they formed?

Answer 7

• Gametes are sex cells
• They are formed in special sex organs called gonads

Question 8

What is the male gamete and where is it produced?

Answer 8

• The male gamete is called a sperm cell and are produced in the male gonads called the testes

Question 9

What is the female gamete and where is it produced?

Answer 9

• The female gamete is called ova (more commonly known as egg) and are produced in the female gonads called the ovaries

Question 10

What is the function of the oviduct (Fallopian tube)?

Answer 10

• the tube through which the ovum moves from the ovary to the uterus

Question 11

What is the function of the uterus?

Answer 11

• The embryo develops here

Question 12

What is the function of the ovaries?

Answer 12

• This produces the ova (eggs)

Question 13

What is the function of the cervix?

Answer 13

• The opening from the vagina to the uterus

Question 14

What is the function of the prostate gland + seminal vesicle?

Answer 14

• Secretes a fluid that mixes with the sperm to produce semen

Question 15

What is the function of the testes?

Answer 15

• This is where sperm are produced

Question 16

What is the function of the sperm duct?

Answer 16

• These tubes carry sperm from the testes to the urethra

Question 17

What is the function of the scrotum?

Answer 17

• The sac that contains the testes

Question 18

What is fertillisation?

Answer 18

• Fertilisation is when the nucleus of the ovum (female sex cell) fuses with the nucleus of the sperm (male sex cell)
• the fusion of female and male gametes to form a new cell called a zygote

Question 19

What is the order in which an egg is fertillised?

Answer 19

1 - Sperm are produced by the testes
2 - During intercourse they pass along the sperm duct (vas deferens)
3 - They mix with the fluid from the seminal vesicles and prostate gland
4 - The mixture is now called semen
5- It is ejaculated into the vagina of the female
6 - The sperm swims through the cervix
7- The sperm swims towards the Fallopian tube to fertilise an ova

Question 20

How many chromosomes does a gamete and zygote have?

Answer 20

• Each gamete has half of the number of chromosomes (haploid)
• Zygote formed by fertillisation has the full number of chromosomes (diploid)

Question 21

What are primary sex characteristics?

Answer 21

• Refer to the changes that occur during puberty to the sexual organs

Question 22

What are some examples of primary sex characteristics?

Answer 22

• Uterus
• Vagina
• Penis
• Testes

Question 23

What are secondary sec characteristics?

Answer 23

• Refer to visible, physical changes that mark adult maturation. They make it clear that the body is now mature enough for reproduction

Question 24

What are some examples of secondary sex characteristics?

Answer 24

• Body hair
• Hips widening
• Breasts start to form
  -Voice deepens
• Growth spurt

Question 25

What is the menstrual cycle?

Answer 25

- The menstrual cycle is one of the secondary sexual characteristics that starts in early adolescence in females (around age 12) - The average menstrual cycle is 28 days long - Ovulation occurs around day 14, with the egg travelling to the uterus - If the egg is not fertilised, menstruation (period) begins due to the breakdown of the uterine lining - Menstruation lasts around 5 - 7 days and signals the beginning of the next cycle - After menstruation finishes, the lining of the uterus starts to thicken again in preparation for possible implantation in the next cycle

Question 26

What are the 4 main hormones that the menstrual cycle is controlled by?

Answer 26

- Oestrogen - Progesterone - FSH (Follicle stimulating hormone) - LH (Luteinising hormone)

Question 27

Where are all the hormones secreted from?

Answer 27

Oestrogen and Progesterone - Secreted from cells in the ovaries FSH and LH - Secreted from the pituitary gland in the brain

Question 28

What is the role of oestrogen in the menstrual cycle?

Answer 28

- Repairs the lining of the uterus after menstruation - Released - day 7-13

Question 29

What is the role of progesterone in the menstrual cycle?

Answer 29

- Completes the development of the uterine lining and maintains it - Increased in production - day 14-23

Question 30

What is the role of FSH in the menstrual cycle?

Answer 30

- It causes an egg to mature in an ovary - It stimulates the ovaries to release the hormone oestrogen - Released - start of the cycle

Question 31

What is the role of LH in the menstrual cycle?

Answer 31

- Causes the mature egg to be released from the ovary - Level of LH peaks - Day 14

Question 32

What changes happen to a developing embryo and a foetus?

Answer 32

- Growth - Excretion - Cell division - Respiration - Differentiation of cells to produce tissue organs and systems

Question 33

What is the role of the placenta?

Answer 33

- The placenta is responsible for providing oxygen and nutrients (glucose and amino acids) and removing waste substances

Question 34

What is the role of the amniotic fluid?

Answer 34

- The foetus is protected by the uterus and the amniotic fluid, a liquid contained in a bag called the amnion - Regulates temperature and acts as a shock absorber