Unit 2 Flashcards
What are tissues
A group of similar cells that work together for a particular function
What are organs
A structure made of a group of tissues working together to perfoerm a function
Name 3 facts about stem cells
They are in specialized cells in animals
They can divide and become specialized cells by variation
Stem cells are needed for growth and repair
Name the 10 places you can find stem cells
Brain, blood vessels, skeletal muscle, peripheral blood, bone marrow, teeth, skin, heart, liver, gut
What are meristems
Sites of cell division in plants
Eg root and shoot tips
What can unspecified meristems do
Grow into specialized plant cells eg xylem
Name the three parts of the central nervous system
Brain
Spinal cord
Nerve cells
Name the three parts of the brain
cerebrum, cerebellum, medulla
State the function of the cerebrum
Controls memory, personality and conscious thought
State the function of cerebellum
Controls balance and coordination
State the function of the medulla
Controls heart rate and breathing rate
What’s is a reflex arc
The sequence of neurons a nervous impulse passes through to cause a reflex action
What is the order of neurons In a reflex arc?
Sensory, relay, motor
What is a reflex action
A rapid automatic response to a stimulus
What’s the sequence in reflex action
Sense receptor, sensory neuron, relay neuron, motor neuron, effector(muscle)
What is a synapse and what happens
A gap between two neurons
Signals are passed across this junction by chemical messengers called neortansmitters
How do signals travel along nerves
By electrical impulses
Name three facts about hormones
Chemical messengers
Made by endocrine glands
Transported around the body by the blood
Which 6 places in e body do you find endocrine glands
Testis, ovary, pancreas, adrenal, thyroid, pituitary
Why is glucose needed
To make ATP
What controls levels of glucose in the blood
Hormones insulin and glucagon
When is glucagon produced
When glucose is gone
When controlling glucose levels in high blood pressure, what are the 4 stages
Too much glucose in blood
pancreas produces more insulin
Increase glucose uptake by cells and glycogen formation
Blood glucose levels decrease
When controlling glucose levels in low blood pressure, what are the 4 stages
Too little glucose in blood
Pancreas,produces more glucagon
Breakdown of glycogen in liver
Blood glucose levels increase
What are all sex cells known as
Gametes
Name 4 facts about sperm
Small
Has tail to swim
Many produced
Contains nucleus
Name 4 facts about female eggs
Large
Less produced
Contains nucleus
Contains food source
When does sexual reproduction occur
When generic information from two sexes are combined
When does fertilization occur
When the nucleus of a male gamete fuses with nucleus of female gamete
What is the cell produced when a male and female gamete fuse called
Zygote
Name the 5 parts of femal reproductive organs
Ovary, cervix, vagina, uterus, oviduct
Explain function of the ovary
Produces eggs
Explain function of oviduct
Tube which links ovary to uterus, site of fertilization
Explain function of uterus
Holds baby until it’s mature enough for birth
Explain function of vagina
Receives penis during sexual intercourse
Name the 4 parts of male reproductive organs
Testes, sperm duct, penis, scrotum
Function of testes
Produce hormones and sperm
Function of sperm duct
Fluid gets added to sperm
Function of penis
Erect during sexual intercourse to deliver semen into vagina effectively
Function of scrotum
Contains the testes and acts as climate control
Name the 7 parts of a flower
Petals, stigma, filament, anther, ovary, nectary, sepal
Explain pollination
The transfer of pollen from the anther of a flower to the stigma
What are specialized cells
Cells which each have a particular structure for a specific job
State 4 facts about insect pollinated plants
Bright color
Smell
Produces nectar
Stricky stigma and pollen
Name 4 facts about wind pollinated plants
Dull
No smell or nectar
Stigma is like a net
Pollen is light
Explain continuos variation
A wide range of values between two extremes eg height
Explain distinct variation
There are distinct groups with no values in between eg eye color
Define chromosomes
Large pieces of DNA
Define genes
Section of chromosomes which codes for a characteristic
Define allele
Different forms of a gene
Define dominant
Allen whose effect always shows in the phenotype
Define recessive gene
Allele whose effect is always hidden in the phenotype
Define homozygous
Alleles in genotype are the same eg BB or bb
Define heterozygous
Alleles in gemstones are different
Define phenotype
The appearance of an organism
Define genotype
The alleles an organism has for a particular characteristic
Define polygenic
A characteristic controlled by more than one pair of genes
Name three things the circulatory system is made up of
Heart
Blood vessels
Blood
Define allele
Different forms of a gene
Define dominant
Allele whose effect always shows in phenotype
Define recessive
Alleles whose effect is always hidden in phenotype
Define homozygous
Alleles in genotype are the same
Define heterozygous
Alleles in gentotype are different
Define phenotype
The appearance of an organism