reproduction and development revision

Question 1

what is sexual reproduction?

Answer 1

the recombination of genetic material from two parents to produce genetically unique offspring that are different from both parents

Question 2

what is asexual reproduction?

Answer 2

the copying and division of one parent cell and it’s genetic material to produce offspring that are identical to their parents and each other

Question 3

why is sexual reproduction useful for?

Answer 3

it’s useful because genetic material is reshuffles the DNA of the new organism through fertilisation. this increases variation which is essential for evolution.

Question 4

why is asexual reproduction useful?

Answer 4

it’s very fast and it makes use of a genetic pattern known to be able to survive the current conditions.

Question 5

what is fertilisation?

Answer 5

fertilisation happens when the nucleus of a sperm cell fuses with the nucleus of an egg cell, taking two gamete’s and forming a zygote.

Question 6

what is a zygote?

Answer 6

a zygote is a fertilised egg cell which is formed when a egg gamete fuses with a sperm gamete

Question 7

what is a gamete?

Answer 7

an egg or sperm cell

Question 8

what is the order of fertilisation?

Answer 8

female gamete nucleus + male gamete nucleus —> zygote —> embryo —> foetus —> baby

Question 9

what is cell division?

Answer 9

cell division is the process by which new cells are made, this is how multicellular organisms grow and repair damage and how unicellular organisms reproduce

Question 10

what is cell division controlled by?

Answer 10

the nucleus

Question 11

what stages do cell division occur in?

Answer 11

• division of nucleus

- division of cytoplasm

Question 12

what is haploid?

Answer 12

haploid cells only contain one set of chromosomes

Question 13

what is the male gamete in plants?

Answer 13

pollen

Question 14

what is the female gamete in plants?

Answer 14

ovule

Question 15

what is the male gamete in animals?

Answer 15

sperm

Question 16

what is the female gamete in animals?

Answer 16

egg (ova)

Question 17

what does diploid mean?

Answer 17

diploid cells contain two sets of chromosomes, this is described as 2n

Question 18

what is mitosis?

Answer 18

mitosis is the process by which cells divide

Question 19

what are the stages of mitosis?

Answer 19

1. chromosomes DUPLICATE themselves
2. chromosomes SUPERCOIL into CHROMATIDS
3. chromosomes LINE UP along the equator and spindle fibres attach to the chromosomes
4. spindle fibres contract, SEPERATING the two sets of chromosomes
5. nuclear membranes reform ALONG THE EQUATOR
6. cytoplasm DIVIDES to form TWO IDENTICAL DAUGHTER CELLS.

Question 20

what is the mitosis mnemonic?

Answer 20

Dont- Duplicates
Look- Lines up
Somebody’s- Separates
Dancing - Divides

Question 21

what is a stem cell?

Answer 21

a stem cell is an unspecialised animal cell which is capable of cell division to make more cells and differentiate into other types of cells.

Question 22

what are three examples of uses of stem cells?

Answer 22

• bone marrow transplant
• cornea transplant
• skin grafts

Question 23

why are embryonic stem cells controversial?

Answer 23

it requires the scientists to kill the embryo and some people don’t agree with killing life for the sake of science

Question 24

what are spindle fibres?

Answer 24

a protein material which helps separate the the chromosomes