SB1 - 3

Question 1

What are the 2 types of stem cells?

Answer 1

Adult stem cells and embryonic stem cells

Question 2

What is the interphase process?

Answer 2

When all sub cellular structures are replicated exactly to 94 chromosomes

Question 3

What is mitosis?

Answer 3

cell division used to produce 2 genetically identical daughter cells

Question 4

Disadvantages of using stem cells in medicine

Answer 4

Ethical issues, causes cancer, immune system may kill of the medicine

Question 5

What is the longest part of mitosis?

Answer 5

The interphase

Question 6

What types of cell do mitosis only take place in?

Answer 6

Diploid (46 chromosomes)

Question 7

How do you calculate plant growth?

Answer 7

Final mass - starting mass
———————————— x 100
starting mass

Question 8

What are meristems and where are they located?

Answer 8

Part of a plant where mitosis happens quickly. Found in plants shoots and roots

Question 9

What can adult stem cells specialise into?

Answer 9

Blood type cells like platelets, red blood cells, whote blood cells, partly specialised immune system cells

Question 10

What are the purpose of receptor cells?

Answer 10

To detect stimuli

Question 11

What are the 2 types of nervous systems?

Answer 11

Central nervous system and peripheral

Question 12

Does a motor neurone contain a dendron?

Answer 12

No but it contains an axon

Question 13

How can we spot the difference between a sensory and motor neurone

Answer 13

Where the cell bodies are placed

Question 14

What is the purpose of dendrites

Answer 14

They receive impulses from receptor cells

Question 15

What is the purpose of the myelin sheath?

Answer 15

Its a fatty later that insulates the neurone allowing electrical impulses to travel faster

Question 16

What is a synapse and neurotransmitter?

Answer 16

Synapse - A gap between 2 neurons they are used for strength and direction
Neurotrasnmiter - chemical released into a synapse

Question 17

What is a reflex arc?

Answer 17

Neurone pathways which bypass parts of the brain involved in processing info

Question 18

Name the 4 parts of the brain and their functions.

Answer 18

Medulla oblongata - controls heart and breathing rate
Cerebral cortex - controls personality, behaviour, language consciousness etc.
cerebellum - posture and balance
brain stem/spinal cord - connects to the spinal cord

Question 19

What is a cataract?

Answer 19

A cataract in the eye is a protein which builds up inside the lens creating a ‘cloudy’ blur in vision.

Question 20

How do short and long sighted people’s vision work?

Answer 20

Short sighted people- have longer eyeballs which means the rays are too short to reach the retina .
Long sighted people- have shorter eyeballs which means the image focuses behind the retina.

Question 21

Why do our pupils either expand or shrink?

Answer 21

Our pupils expand or shrink to protect the eye from damage. Its a reflex action.

Question 22

List the parts of the eye and their processes.

Answer 22

*use sticky notes

Question 23

How is food moved through the digestive system?

Answer 23

peristalsis

Question 24

What is asexual reproduction and what are advantages and disadvantages?

Answer 24

Asexual reproduction - doesn’t require fertilisation, only requires 1 parent.

advantages - much quicker, only 1 parent, ideal for areas that have unequal amounts of gender.

disadvantages - both vulnerable to disease since they are both genetically identical.

Question 25

What is asexual reproduction most rare and common in.

Answer 25

rare in vertebrates. common within invertebrates.

Question 26

What is meiosis?

Answer 26

A type of cell division used to produce haploid gametes.

Question 27

What is a gene and genome?

Answer 27

gene - a section of DNA which contains instructions to make a protein. genome - all of an organisms DNA

Question 28

Explain the process of meiosis.

Answer 28

1st the interphase happens 2nd the chromosomes split into pairs 3rd the pairs then separate again into 2 haploid gametes

Question 29

What are the 4 bases in DNA?

Answer 29

A - Adenine T - Thymine C - Cytosine G - Guanine

Question 30

What makes genes slightly different from person to person?

Answer 30

Because we have little differences in our genes caused by slightly different orders of bases in our DNA.

Question 31

What forms the backbone of a double helix?

Answer 31

Sugars (deoxyribose) Phosphates

Question 32

Describe the stage of transcription (1) during protein synthesis.

Answer 32

1. Enzyme RNA polymerase binds to a non-coding section of DNA 2. Enzyme separates DNA strands 3. RNA polymerase adds complimentary RNA nucleotides to template strands 4. Nucleotides link forming a mRNA

Question 33

Describe the stage of translation (2) during protein synthesis.

Answer 33

1. mRNA strand travels out nuclear pores 2. mRNA strands attach to ribosomes 3. Ribosomes move along mRNA strand 3 bases at a time -each 3 bases is called a codon. 4. At each codon a molecule of tRNA with complimentary anticodons line up. - each tRNA molecule carries a specific amino acid 5. As ribosomes move along it joins amino acids together forming a polypeptide.

Question 34

What is cystic fibrosis caused by?

Answer 34

A recessive allele

Question 35

How is your blood group determined?

Answer 35

By the type of marker molecules you have on the outside of your red blood cells.

Question 36

what is the definition of codominant?

Answer 36

when both alleles for the gene affect the phenoytype

Question 37

explain sex linked disorder in males and females.

Answer 37

If a males Y chromosomes is missing some genes found on the X chromosome this means the male will only have one allele for some of the genes on the X chromosome. If the allele for one of these X chromosome genes causes a genetic disorder the man will develop this disorder. since females have the same chromosomes (XX) she will have a healthy allele on her other X chromosome. If the disorder allele is recessive she wont get the disorder.

Question 38

What is a sex linked disorder

Answer 38

disorders that show a different pattern of inheritance in men and women

Question 39

What is variation and the 2 types?

Answer 39

Changes in the characteristics of an individual within a population. 1. Genetic variation - where different alleles are inherited during sexual reproduction. 2. Environmental variation - Where your characteristics are affected by your surroundings.

Question 40

What is discontinuous and continuous variation? And how can it be shown?

Answer 40

Discontinuous - where data can only take a limited set of values. Frequency bar chart with gaps Continuous - where data can be any value in a range. Frequency bar chart without gaps.

Question 41

how is a calorimeter used?

Answer 41

As the food burns, energy is transferred by heating to the water. The change in temperature of the water is a measure of the amount of energy released from the food.