BIO - TRIALS REVISION

what cells are involved in both the cell-mediated and humoral response?

T-helper cells

what is the main role of the lymph system in the immune response?

holding record of previous infections

what is the cell-mediated response?

T-cells - of adaptive immune system

what is humoral immunity from?

B-cells - antibody-mediated response of adaptive immune system

what does gel electrophoresis seperate DNA/RNA/proteins based on?

molecular size

what are the causes of variation in cell replication?

mutations

is vector transmission direct or indirect?

indirect

what type of cells are produced from mitosis?

somatic cells

what type of cells are produced from meiosis?

gametes

how many cell divisions are in mitosis?

1

how many cell divisions are in meiosis?

2

how many daughter cells are made in mitosis?

2 daughter cells

how many daughter cells are made in meiosis?

4 daughter cells

what are the three types of adaptations & what do they involve?

• structural (body shape or color)

• physiological (internal body processes)

• behavioral (actions or habits)

what does diploid mean?

2 sets of chromosomes (2× 23)

what phase occurs before prophase in meiosis & mitosis?

interphase (not included in PMAT)

what source of variation occurs in meiosis prophase 1?

crossing over

are gametes haploid or diploid?

haploid (half of 46 full chromosomes > 23)

what is the strongest visual cue for X-linked recessive traits on a pedigree?

partner & immediate children of male are unaffected, but the trait skips to grandsons

• "skips to the grandsons via daughters (carriers)”

what is DNA sequencing?

finding the exact order of the four chemical bases that make up an organism's genetic code (DNA)

what is DNA profilling?

using polymerase chain reaction & gel electrophoresis, it identifys similarities in the length of short-tandem repeats (STRs)

what chemical is released to reduce glucose levels in blood?

insulin

what are the steps of DNA profiling?

1. extraction

2. amplification

3. digestion (seperates STRs)

4. gel electrophoresis

what are the two cell types B cells differentiate into?

plasma B-cells & memory B-cells

what term is used describe the normal amount in a homeostasis negative-feedback mechanism?

the ‘set point’

what is used as an alternative to thymine, as it uses less energy?

uracil

when is uracil substituted for thymine?

during synthesis of RNA molecules

what is Koch’s 1st postulate?

the microbe causing the disease must be found in each diseased organism

what bonds two nucleotide bases together in the double-helix DNA structure?

hydrogen bonds

what do closing stomates prevent when maintaining water balance?

transpiration

what are two examples of ways plants maintain water balance?

• Banksias have woody fruits rather than fleshy fruits. This prevents loss of water when the fruits fall to the ground.

• Eucalypts have leaves that hang vertically. This reduces exposure to direct sunlight, which would cause loss of water by evaporation.

what type of non-infectious disease is skin cancer NOT?

genetic disease

what does the hormone FSH stand for?

follicle-stimulating-hormone

what is the role of FSH?

rise in the levels at start of the cycle stimulates the growth of the follicle in the ovary

what causes a rapid rise in luteinizing hormone?

follicle secreting oestrogen

what does oestrogen do?

builds up endometrium lining

what does progesterone do?

maintains endometrium lining when pregnancy occurs

what are two functions of the kidney?

• regulate the salt and water concentration of blood

• filter the blood to remove harmful substances

what does gel electrophoresis involve? (DNA profilling)

an electric current pushes negatively charged DNA or protein molecules through the gel & seperates the STRs based on length

what two processes use both PCR & gel electrophoresis ?

DNA profilling & DNA sequencing

what should be mentioned in recombinant DNA, DNA sequencing & DNA profilling?

restriction enzymes

what do restriction enzymes involve in biotechnology?

cut double-stranded DNA at specific target sequences, producing sticky or blunt ends

what structure of a plant is equivalent to the testes in an animal?

anther

what structure of a plant is equivalent to the vagina in an animal?

the stigma

what part of the immune system are lymphocytes part of?

adaptive

what is a nonsense mutation in coding DNA?

premature stop codon, which shortens the polypeptide and usually results in a non-functional protein

what is the difference between chromosomal mutations & point mutations?

point mutations affect a single nucleotide, while chromosomal mutations alter large segments or entire numbers of chromosomes

what is a homozygous genotype?

genotype where both allelles are identical

what is a heterozygous genotype?

genotype where both alleles are different

what is a phenotype?

observable characteristics based on genotype and environmental factors

what is a gene?

a portion of DNA that codes for a characteristic

What happens to the corpus luteum if the egg is fertilised?

It is maintained and keeps secreting progesterone; it's kept active by hCG released by the developing embryo

What happens to the corpus luteum if the egg is not fertilised?

It degenerates around day 24

What happens to progesterone and oestrogen levels if fertilisation occurs?

They remain high, sustained first by the corpus luteum, then by the placenta

What happens to progesterone and oestrogen levels if fertilisation does not occur?

They fall sharply as the corpus luteum degenerates

What happens to the endometrium if the egg is fertilised?

It is maintained and continues developing, providing the site for implantation and nourishment of the embryo

What happens to the endometrium if the egg is not fertilised?

It is no longer maintained and breaks down and is shed

Does menstruation occur if the egg is fertilised?

No, menstruation does not occur; the cycle is paused for pregnancy

Does menstruation occur if the egg is not fertilised?

Yes, menstruation occurs and marks day 1 of the next cycle

What happens to FSH and new follicle development if fertilisation occurs?

FSH stays suppressed by high progesterone, so no new follicles develop

What happens to FSH and new follicle development if fertilisation does not occur?

FSH rises again as progesterone and oestrogen fall, removing negative feedback, and a new follicle begins developing

Is there a detectable hormone marker if the egg is fertilised?

Yes, hCG is present, which is the basis of pregnancy tests

Is there a detectable hormone marker if the egg is not fertilised?

No, hCG is not produced

what hormones peak during ovulation?

luntenizing hormone (LH), follicle stimulating hormone (FSH) and estrogen

what are the non-cellular types of pathogens?

viruses & prions

what is gene transfer?

the movement of genetic material (DNA or RNA) between organisms or cells

when does crossing over occur in meiosis?

prophase 1

what secretes hormones in the negative feedback cycle involving blood glucose?

the pancreas

what hormone is released by the pancreas when there is a fall in blood glucose? (below optimal)

glucagon

what hormone is released by the pancreas when there is a rise in blood glucose? (above optimal)

insulin

what is glucose transformed into when its levels within the blood are too high?

glycogen

what is a fungus adaptation that facilitates invasion of the host?

cell wall-degrading enzymes that break down the plant's cell walls, allowing the fungus to penetrate root tissue and invade the host