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What are chromosomes?
They are spindle shaped cells located in the nucleus of a plant and animal cell. It carries genetic data that is required for the growth of the cell and the living survival of the living organism.
What is a chromosome complement?
It would have a specific typical value of chromosomes
How many chromosomes does a human have in total?
46
How many chromosomes do you inherit from your parents
23
What is a diploid?
A cell which has a identical number of chromosomes
How many chromosomes does a sperm cell contain?
23 unmatched chromosomes
What is a haploid?
A single pair of chromosomes
What is Mitosis?
It is the procedure when the nucleus splits into two daughter nuclei each of which gets the same amount of chromosomes that were existing in the old nucleus
What is the first stage of Mitosis?
As each chromosome becomes smaller and larger it is seen to be a 2 stranded thread. The two chromatids have followed from the same copy of a chromosome. They would be held together by a centromere
What is the second stage of mitosis?
The nebular membrane vanishes and a axis is created. Each chromosome becomes linked by its centromere to one of the axis at the equator.
What is the third stage of mitosis?
Each centromere divides and one chromatid from each group transitions to the north pole and one to the south pole.
What is the final stage of cell division?
The nuclear membrane forms around each group of chromatids and nuclear cell division is complete
What happens in Interphase (resting phase)
Each cell now would be involved a moment of cell development. During the event the chromosomes in each nucleus cannot be seen. During this time each chromosome is completely uncoiled and being involved in a copying process. This means a exact copy of the chromosomes is formed for the next nuclear division.
What are stem cells?
They are unspecialised animal cells involved in growth and repair
What are embryonic stem cells?
They are able to become all types of cells found in the human body. They even posse the ability to make a new organ from a few cells.
Where can embryonic stem cells be found?
Bone marrow
Blood
Skin
Why are embryonic stem cells so useful?
In a normal environment tissue stem cells are only allowed to fill up the amount of one or more types of specialised cell not far off related to the tissue which they are located.
What amount of skin do you need to take to obtain stem cells?
small sample
What are cells?
They are the normal parts of life because it is the smallest part that can lead and alone life.
What is a tissue?
A area of cells which role is to do a specific task
What is a Organ?
A area that is made up of unique tissues instructed to do one or more tasks
What is a system?
A section of similar tissues and organs
What is the function of the epithelial cell?
Defence against mouth lining
What is the function of red blood cells?
Take oxygen to the alive cells
What is the function of white blood cells?
destroying pathogens
What is the function of the motor neuron?
sending nerve impulses
What is the function of the goblet cell?
section of mucus which holds dirt and germs
What is the function of the ciliated epithelial cell?
pushing dirty mucus up and not near the lungs
What is the function of the smooth muscle cell?
Food being transported through the oesophagus by peristalsis
What is the function of the epidermal cell?
protection
What is the function of the guard cells?
Allowing gas exchange by altering the structure allowing the stomata to open and close
What is the function of the palisade mesophyll?
The main section of photosynthesis
What is the function of the spongy mesophyll?
The second section of photosynthesis
What is the function of the sieve tube?
The movement of substances that can be dissolved in water that are pushed up and down
What is the function of the companion cell?
In charge of the sieve tubes function
What is the function of the vessel?
Protect and take water up the plant
What is the function of the epidermal cell?
protection
What is the function of the root hair cell?
Taking in all the water and minerals
What is the function of the stomach?
Breaking down foods
What is the function of the heart?
Supply blood around the body
What is the function of the kidney?
Getting rid of toxic waste and storing water
What is the function of the lungs?
The exchange of repository gases
What is the function of skin?
Protecting the body from anything harmful and keeping a optimal temperature
What is the function of the root?
Taking in water
What is the function of the stem?
Move water and substances that dissolve in water
What is the function of the leaf?
Photosynthesis and gas exchange
What is the central nervous system made up of?
Brain
Spinal Cord
Nerves
How does the CNS work?
The nerves attached to the organs make sure that there is good cooperation with all body parts
What are the 4 parts of the brain?
Medulla
Cerebellum
Cerebrum
Spinal cord
What is the function of the medulla?
It would control how fast you breath and your heart speed
What is the function of the cerebrum?
Stores information
What is the function of the cerebellum?
It controls how you stay still and the way you walk
What is the function of the sensory nerve?
It takes information from the body’s receptors to the CNS
What is the function of the motor neuron?
It takes nerve impulses from the CNS to the body’s effectors
Why are theses nerve impulses important?
It is to make sure the brain is aware about all areas of the body and its surroundings
What does the body do when it responds to a reflex action?
The CNS would send out nerve alert to the right effector such as muscle or a gland. The muscles would be more big than from the gland
What are neurons?
A cell body linked to a nerve fibre
What is a reflex arc?
A electrical impulse that is directed towards the cell body of a neuron by a sensory fibre and distance from it by a axon fibre.
What is the synapse?
Chemicals at connections pass information from one neuron to another through sensory neurons to the central nervous system (CNS). Interneurons help streamline these responses.
What happens after the neurons are collected?
It is taken by sensory neurons to the CNS to be made. Nerve impulses are then taken via neurons to motor neurons which allows a reaction to happen by and effector.
How do pain receptors work?
The data is normally transferred to the brain as electrical impulses via nervous systems, which does a broad collection of joined sections of transmission. They are in all sense organs.
Why are pain receptors important?
When the brain gets nerve impulses from pain receptors. It is useful because it makes the person alerted on the tragedy that could occur.
What is a reflex action?
The sending of a nerve impulse through a reflex arc in a reflex action. It is a normal response to a stimulus
What are hormones?
They are chemical messengers secreted directly into the bloodstream by endocrine glands
What do hormones do?
They activate particular reactions in target tissues by joining to receptor proteins on their area giving access to make a identical copy. Tissues that don’t have these receptors do not react to the hormone.
What happens if blood glucose levels are low?
The water concentration of the blood will fall and water will diffuse out of cells by osmosis
What happens if blood glucose levels fall to much?
Then body cells will not receive as much glucose and so will not be able to release as much energy in respiration.
How is blood glucose levels controlled?
By the action of the hormones insulin and glucagon. The target cells of these hormones are found in the liver.
The liver acts as the body's glucose 'reservoir'. Liver cells can take in glucose molecules from the blood using insulin and store them in the form of glycogen
What is glucagon?
A hormone produced by the pancreas that promotes the breakdown of glycogen into glucose in the liver.
What is sexual reproduction?
New organisms are made from the combining of the nucleus of a male sex cell with the nucleus of a female sex cell. Sex cells are also known as gametes. Male gametes are made by male reproductive structures. Female gametes are made by female reproductive structures.
Where does male gamete production occur?
Sperm are constantly produced in the testes of adult male mammals. During sexual intercourse sperm cells travel through the sperm duct into the urethra and are released out of the end of the penis.
Where does female gamete production occur?
Egg cells are produced in the ovaries of the female mammal. Eggs are released from the ovaries into the oviducts.
What is the function of the sepals?
Protect the unopened flower bud
What is the function of Petals?
May be brightly coloured to attract insects
What is the function of the Stamens
The male parts of the flower consisting of the anther held up on the filament
What is the function of the Anthers?
Produce male gametes (in pollen grains)
What is the function of the Stigma?
The top of the female part of the flower which collects pollen grains
What is the function of the Ovary?
The bottom of the female part of the flower which makes the female gametes (ovules)
What is the function of the Nectary?
To produce sugary nectar and attract insects
What is Fertilisation?
The fusing of the nucleus of the haploid male gamete to the nucleus of the haploid female gamete to create the first cell of the new individual
What is a phenotype?
The particular version of a characteristic seen in an individual
What is Discrete variation?
Characteristics controlled by a single gene (one copy inherited from each parent) tend to have phenotypes that fall into separate categories
What is Continuous variation?
It would be able to show a wide range of values
What is a gene?
a location on a chromosome where there is a DNA base sequence that codes for a protein that controls a particular characteristic.
How many copies of chromosomes do you receive from your parents
An person would get two sets of the gene for each characteristic. One set is carried on a chromosome passed on by the male gamete and one on the matching chromosome passed on by the female gamete.
What does homozygous mean?
If the two alleles of a particular gene are identical
What does heterozygous mean?
If the two alleles of a particular gene are different
What are alleles?
Different forms of a gene that produce different phenotyp
What does Dominant mean?
An allele that always produces a certain phenotype in an organism. It is represented by a capital letter.
What is a Genotype?
An individual's alleles for a particular characteristic
What does Recessive mean?
An allele whose effect on the phenotype can be masked by a dominant allele of the same gene. It is represented by a lower case letter.
What is the function of Large surface area (Plants)
Maximise light absorption
What is the function of a thin leaf?
Short distance for carbon dioxide to diffuse into leaf cells
What is the function of a Thin waxy cuticle?
Protects the leaves without blocking out light
What is the function of the Thin transparent epidermis?
Allows light to reach the palisade mesophyll cells
What is the function of the xylem?
Water and minerals are transported up through the plant stem
Why does the xylem have lignin rings?
This allows the xylem to withstand pressure changes as water moves through the plant.
What is the function of the phloem?
Sugar produced by photosynthesis in the leaves is transported up and down the plant to the meristems and other tissues
What is the function of the companion cells?
provide the energy for the sieve cells
