Simple inheritance in animals and plants

Question 1

What is mitosis

Answer 1

The type of cell division that produces identical new cells

Question 2

In body cells how are chromosomes found

Answer 2

In pairs

Question 3

Why do body cells need to divide

Answer 3

To produce new cells for growth or repair

Question 4

What do chromosomes contain and what must be done with them

Answer 4

Genes/alleles

They must be passed on to each new cell

Question 5

When do most animal cells differentiate

Answer 5

Early in development and cell division mainly for repair and replacement

Question 6

Describe the cell division process of mitosis

Answer 6

The normal body cell has four chromosomes in two pairs
as salsa vision starts a copy of each chromosome is made
The cell divides into two forms of two daughter cells
Each daughter cell has a nucleus containing four chromosomes identical to the ones in the original parent cell

Question 7

What is meiosis

Answer 7

The two stage process of cell division which reduces the chromosome number of the daughter cells

Question 8

Explain how four gametes are formed from one cell

Answer 8

There are two sets of cell division a body cell divides into two and each divides again

Question 9

What do gametes have

Answer 9

One set of chromosomes other body cells have two sets

Question 10

What does sexual reproduction result in

Answer 10

Variation as the gametes from each parent fuse so half the genetic information comes from the father and a half from the mother

Question 11

Where are stem cells found in adult humans

Answer 11

In bone marrow

Question 12

What is a stem cell

Answer 12

A stem cell is an undifferentiated cell that can form into many varieties of different cell types when required

Question 13

What can Stem cells be used to cure

Answer 13

Conditions such as paralysis e.g. by differentiating into new nerve cells

Question 14

Where else can stem cells be found

Answer 14

in the human embryo

Question 15

What are some ethical issues to do with extracting stem cells from embryos

Answer 15

The embryos are sometimes destroyed

The embryo does not give consent

Question 16

What are some advantages for using stem cells from embryos as opposed to using stem cells from bone marrow

Answer 16

Stam cells from embryos can differentiate into all the cells the body needs whereas stem cells found in bone marrow can only change in some limited types of cells e.g. blood cells

Question 17

Which scientist worked out how characteristics are inherited

Answer 17

Gregor Mendel

Question 18

What are chromosomes

Answer 18

Large molecules of DNA

Question 19

What is a gene

Answer 19

A small section of DNA

Question 20

What structure does DNA follow

Answer 20

Double helix

Question 21

What does a gene code for

Answer 21

Each gene codes for a particular combination of amino acid which make a specific protein

Question 22

What can a unique DNA pattern be used to identify

Answer 22

Peoples identity by their DNA fingerprint

Question 23

Which sex chromosomes are found in human males

Answer 23

X and Y

Question 24

What is meant by the term phenotype

Answer 24

This is a description of the physical characteristics

Question 25

What is sex determined by

Answer 25

The X and Y chromosomes

Question 26

What are alleles

Answer 26

Different forms of a gene

Question 27

What is a recessive allele

Answer 27

And allele where the effect is masked

Question 28

What is a dominant allele

Answer 28

An allele that masks the effects of another

Question 29

Name one Genetic disorder which is controlled by a dominant allele

Answer 29

Polydactyly

Question 30

What are the chances of a child having cystic fibrosis if one parent has the disorder and the other parent is heterozygous

Answer 30

50% as one parent has to pass on the allele the other parent has a 50% risk of passing it on

Question 31

What is cystic fibrosis is caused by

Answer 31

A recessive allele

Question 32

What are genetic diagrams used for

Answer 32

To predict the chances of inheriting the disorder

Question 33

What is embryo screening

Answer 33

Tests are carried out on the embryo to diagnose possible disorders

Question 34

What type of stem cells be used in medical research and treatments

Answer 34

Embryonic stem cells

Question 35

What do we mean by heterozygous individual

Answer 35

The individual has one dominant and one recessive allele is for a condition

Question 36

Where can embryonic stem cells be taken from

Answer 36

Spare embryos from IVF or created from adult cells or may be taken from the umbilical cord of newborn babies

Question 37

How many chromosomes does a human have in each body cell

Answer 37

23 pairs, 46

Question 38

What molecules are Genes made out of

Answer 38

DNA

Question 39

What is meant by the term genotype

Answer 39

The types of genes present in the cells

Question 40

Which type of cell division produced two identical cells from the original cell

Answer 40

Mitosis