genes and inheritance

Question 1

what is a chromosome + where are they found

Answer 1

long threads of DNA, found in the nucleus of a cell

Question 2

what is DNA + where is it found

Answer 2

a chemical made up of long molecules with a shape like a twisted ladder (double helix) , it is found in the

Question 3

what are genes + where are they found

Answer 3

part of a chromosomes that determine a feature of an organism

Question 4

how many chromosomes(and pairs of chromosomes) are there in a cell

Answer 4

46 chromosomes
23 pairs of chromosomes

Question 5

what is a nucleus

Answer 5

the structure in a cell that contains the chromosomes

Question 6

what is a gamete

Answer 6

sex cells (female - egg cell, male - sperm cell) ; two gamete fuse together to produce a zygote

Question 7

what is a zygote

Answer 7

a cell formed when a male and female gamete fuse together; it is the beginning of new life

Question 8

how many genes are there on chromosome 1

Answer 8

2000

Question 9

why can’t you usually see the chromosomes in a cell, even when you use a microscope

Answer 9

you can only see chromosomes when a cell is dividing

Question 10

how do scientists number chromosomes

Answer 10

scientists number chromosomes according to how long they are

Question 11

name the different parts of the sperm cell and where they are located

Answer 11

nucleus containing 23 chromos - top of sperm
small amount of cytoplasm - right under top
tail, which produces swimming movements - tail/long thing
cell surface membrane

Question 12

name the different parts of the egg cell and where they are located

Answer 12

nucleus containing 23 chromosomes - smallest circle
cytoplasm, containing food reserves - middle sized circle
cell surface membrane - out side of middle sized circle n

Question 13

why do gametes only have 23 chromosomes

Answer 13

they have only 23 chromosomes bcus when they come together the new cell they create has 2 sets of 23 which is 46 like every other cell

Question 14

fertilization

Answer 14

the fusing together of female and male gametes

Question 15

inheritance

Answer 15

passing on dna from parents to offspring

Question 16

gene

Answer 16

sequence of dna

Question 17

variation

Answer 17

differences between individuals belonging to the same species

Question 18

genetic differences

Answer 18

differences between individuals that are caused by differences between their genes

Question 19

what are the two things that effect variation + examples

Answer 19

environment - body mass
dna - hair, eye or skin colour

Question 20

natural selection

Answer 20

the increased chance of survival of individuals that have particular advantageous features, these individuals have a greater chance of survival and passing on their genes

Question 21

who came up with the natural selection theory

Answer 21

charles darwin

Question 22

what is the natural selection theory

Answer 22

it is the theory that says that the organisms that adapt the best survive