biology Yr 11 final exam IB

antibodies

y-shaped proteins with binding sites produced by plasma cells in response to the presence of an antigen

antigens

molecules the body identifies as foreign based on surface proteins and molecules

disease modes of transmission

vectors (from another species)

vertical (mother to fetus)

antibiotics

compounds blocking growth and reproduction of bacteria. only works on bacteria. targets structures only bacteria have (eg, cell wall)

vaccines

injections containing weakened/killed pathogens. stimulate immune system and prompt the body to produce antibodies to the disease.

eukaryotes

eukaryotic cells have membrane bound organelles with DNA. all living organisms except bacteria.

prokaryotes

bacteria, unicellular, simplistic.

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prokaryote vs prokaryotic

prokaryote = the organism

prokaryotic = type of cell

viruses

not made of cells and require a host. particles of nucleic acid, protein and lipids. are the core of DNA/RNA. coated in a protein called capsid.

pathogen

organism or agent able to cause disease

internal fertilization vs external fertlization

internal - fusion of gametes inside the body of a parent

external - fusion of gametes outside the body of a parent.

mitosis

form of cell division that produces 2 genetically identical daughter cells.

diploid (2n) = full set of chromosomes in each cell.

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reasons for mitosis

maintenance (repair/replacement)

organism growth

SRY - gene

located on y-chromosome

causes gonads to secrete testosterone causing male development.

zygotes

fertilised cell (egg and sperm)

gametes

reproductive cell of an animal or plant (egg and sperm)

a body cell divides so there is half the genetic info in the process of meiosis.

mRNA

molecule containing the instructions or recipe that directs the cells to make a protein using its natural machinery.

how many chromosomes does DNA have?

* 46 chromomes
* 23 pairs

what is a chromosome

a structure found inside the nucleus of a cell.

type of neurons

motor, sensory, relay

motor neuron

communicate info from the brain to tissues and organs throughout the body allowing for movement

sensory neuron

take sensory info from environment

relay neuron

the majority. transmit info from between sensory and motor neurons.

nodes of ranvier

gaps between the myelin sheaths. electric impulses traveling down the axon are able to jump between the nodes

function of nerve fibers

transmit signals over long distances very quickly. to facilitate this, nerve axons are covered by an insulating lipid myeling sheath protected by schwann cells.

cell body

contains the nucleus and majority of the organelles and cytoplasm.

axon

long, narrow ‘arm’ that carries electric signals

dendrites

short, balanced fibres that receive and transmit signals to other cells.

neurons

cells that transmit electrical signals to/from the brain and muscle/glands.

effector

a body part that carries out a response to the stimulus

how do neurons transmit info?

in the form of impulses

spinal chord

sends an impulse to the appropriate effector which will cause the response to the stimulus.

brain

receives nerve impulses from receptors that have detected a stimulus.

chemoreceptor

responds to specific chemicals

temp receptors

respond to changes in temp

photo (light) receptors

respond to changes in light energy

receptor

specialised sensory cell that can detect a stimulus in an organisms environment. send signals to the CNS

function of the nervous system

detects, relays and co-ordinates info about an organisms internal and external environment

nervous system structure

CNS - brain + spinal chrod

PNS - attached to CNS, nerves and receptors

heterozygous

different alleles

trait

a characteristic a parent can pass on to an offspring. is controlled by the proteins made from DNAs instructions

asexual reproduction

produces genetically identical clones. comes from one parent

sexual reproduction

process involving the fusion of the nuclei of two gametes to form a zygote (genetically different offspring.)

genotype

genetic makeup of an organism. written in letters and represents alleles inherited.

phenotype

expressed genotype, physical looks

DNA full name

Deoxyribonucleic Acid

where is DNA found?

in the nucleus of a eukaryote.

in the cytoplasm of a prokaryote

what does DNA do?

controls all activities of a cell

whats DNA made of?

nucleic acid made of smaller building blocks called nucleotides

parts of a nucleotide

1. deoxyribose structure (5 carbons, pentagon)
2. phosphate group
3. nitrogen base

nitrogenous bases

Adenine + thymine

Cytosine + Guanine

what is a gene

a segment of DNA. each gene controls a different trait. humans have over 20,000 genes.

genomes

a list of all ATGC bases coded into our chromosomes. whole genetic info of an organisms. used in GMOs

homozygous

same allele

heredity

set of traits an organism receives from it’s parents

alleles

a pair of two or more genes at a given area of a chromosome.

homeostasis

biological state of equilibrium. the nervous and endocrine systems are responsible from maintianng it.

gonads

develop into either testes or ovaries

meiosis

produces gametes

4 genetically unique daughters.

haploid (n) = half the number of chromosomes in daughter cells

cell strcuture

1. cytoplasm
2. nucleus
3. cell membrane
4. mitochondrion

parts of a flower

1. petal
2. stamen
3. anther
4. filament
5. sepal
6. stigma
7. style
8. pistil
9. ovary
10. ova (eggs)
11. stem

female reproduction

1. vagina
2. cervix
3. myometrium
4. uterus
5. fallopian tube
6. -
7. ovary
8. endometrium

male reproduction

a. testicles

b. vas deferens

c. bladder

d. glans

e. epyidimus

f. prostate

g. seminal vesicle