biology term 1 Flashcards
what does MRSGREN stand for
movement respiration sensitivity growth reproduction excretion nutrition
give a description and example of the life process of movement
All organisms have the ability to move
in most, this is allowed by a muscle pulling a bone
some muscles such as the heart move on their own
most human cells do not have movement, some however do such as blood cells or sperm cells
eg- moving from class to class
how many of the 7 life processes does an organism need to carry out if it is living
all 7
give a description and example of the life process of reproduction
reproduction is a necessary function of all organisms so as to continue the species
humans reproduce by sexual reproduction - a male sperm combines with a female ova that will form a human.
cellular reproduction also occurs in humans
eg- cellular reproduction occurs in the lungs every less than two days
give a description and example of the life process of sensitivity
the body responds in an appropriate way to things such as pain, light, heat, temperature or cells becoming dehydrated.
these responses can occur inside and outside the body
some are voluntary, some are automatic
eg- pupils dilating in the dark to let in as much light as possible
give a description and example of the life process of growth
most organisms, growth does not occur evenly
for example, a human brain will double in size within the first year after birth, whereas the sexual organs only begin to function during puberty.
animals eventually stop growing, plants do not
animal cells do however continue to multiply or enlarge
eg- muscles increase in size as a result of exercise because the muscle cells enlarge
give a description and example of the life process of respiration
reparation is a process in which energy is releases from food
process occurs inside the cell
cellular respiration uses oxygen to break down glucose (food) to carbon dioxide and water
eg- glucose broken down into carbon dioxide and water which is used form things such as cell movement, cell division or building up co flex molecules
give a description and example of the life process of excretion
chemical reactions in the cells produce some substances that the body is not able to use and if not excreted can affect body functions
eg- cellar respiration produces carbon dioxide which cannot be used by the cells and so is excreted through the lungs
give a description and example of the life process of nutrition
feeding or ingestion’s taking food or drink into the body through the mouth
this food contains the nutrients the human body needs to function and the glucose which is converted into energy in cellular respiration
a variety of food groups such as lean meats, fruit and vegetables, some dairy and some carbohydrates are needed for the human body to function
eg- protein needed to build muscle
list the 5 levels of organisation in order
cells tissues organs organ systems organism
give a description and example of the level of organisation of the cell
building blocks of organisms
may serve a particular function within the organism
eg- red blood cell, white blood cell, nerve cells, sperm cells, ova
give a description and example of the level of organisation of organs
made up of two or more tissues
tissues work together to perform a task
eg- heart, stomach, lungs, brain
give a description and example of the level of organisation of organ systems
various organs are organised into systems
group of organs will work together to carry out a task
eg- digestive, respiratory, nervous, skeletal;, muscular, reproductive
give a description of the level of organisation of organism
all of the body systems work together to produce a functioning organism
no system can work in isolation
give a description of the level of organisation of tissue and name all 4 types of tissue
group if cells that are similar in structure and work together to perform a particular task epithelial tissue conective tissue muscle tissue nervous tissue
give description and examples of epithelial tissue
covering or lining tissue
cells closely joined together forms smooth surface
vary in shape
eg- outer layer of skin, lining inside of mouth
give description and examples of connective tissue
provides support of body and helps hold all parts together
cells separated by large amounts of material called matrix
eg-
cartilage - external ear, tip of nose, joints
bone
ligament snd tendons
give description and examples of muscle tissue
three types
able to reposed to stimulus by contracting and becoming shorter
made up of long, thin muscle fibres
-three types-
1. skeletal- attached to bones, voluntary control, eg- bicep, tricep
2. cardiac- makes up heart, involuntary, ego- heart
3. smooth- found in internal lining of organs, made up of neurons , messages can be carried along the fibre, found in brain, spinal chord, nerves`
list all functions of the animal cell and what they do (8)
- cell membrane
- outer protection of the cell
- allows materials in and out of the cell - cytoplasm
- jelly like fluid where chemical reactions take place - mitochondria
- produces and realises energy
- where cellular respiration occurs - nucleus
- contains DNA (deoxyribonucleic acid) - nucleolus
- contains RNA (ribonucleic acid) - golgi body
- packages worn out debris - rough endoplasmic reticulum
- contains ribosomes (where protein synthesis occurs)
- makes proteins - smooth endoplasmic reticulum
- packages lipids (fats)
list all functions of the plant cell and what they do (7)
- cell membrane
- outer protection of the cell
- allows materials in and out of the cell - cytoplasm
- jelly like fluid where chemical reactions take place - mitochondria
- produces and realises energy
- where cellular respiration occurs - vacuole
- contains watery sap
- storage of water/ nutrients/ waste - nucleolus
- contains RNA (ribonucleic acid) - cell wall
- very rigid boundary the protects the cell - chloroplast
- contains green pigment which traps sunlight for photosynthesis to occur
name the four nitrogen bases and what they pair with
adenine (A) - thymine (T)
guanine (G) - cytosine (C)
in RNA (instead of DNA), thymine (T) is replaced with uracil (U)
what is DNA
- deoxyribonucleic acid
- composed of two strands called as daybed helix
- mostly found in nucleus
- contains genetic code
what are choromosomes (2)
- long, thin, thread-like structures found in the nucleus
- each chromosome is a very long DNA molecule wrapped around proteins
how many chromosomes do humans have
46
23 from mother, 23 from father
two types of chromosomes and explain each
autosomal chromosomes -first 22 -determine eye colour, hair colour, any genetic diseases ect sex chromosomes - female XX - male XY
how to interpret dan strand
- read in threes
- bases must match
what are genes
genes are sections of DNA on a chromosome
each gene codes for a particular protein. Name the three proteins and give examples
- structural- collagen (found in tendons and ligaments) and keratin (found in skin, hair, nails, scales and feathers)
- enzymes- amylase (helps digest starch) and lactase (helps digest lactose)
- regulatory- growth hormone ( stimulates growth and cell reproduction) and insulin (controls blood and glucose levels)
replication
- copying DNA
- DNA needs to be constantly replicated to replace old or dying cells and for growth
- very fast, complex process
first stage of replication
the DNA strand will undergo replication.
second stage of replication
the two strands of DNA will be unzipped by an enzyme called DNA Helicase
third stage of replication
one strand of DNA will be copied
free nucleotides will begin their complimentary base
fourth stage of replication
once the new nucleotides have lined up on the strand, they will be joined together by an enzyme called DNA polymerase
stage five
new nucleotides are completely joined
two identical strands of DNA
cell division
for an organisim to grow, they need to replicate their cells
mitosis six stages
IPMATC interphase prophase metaphase anaphase telophase cytokinesis
mitosis vs meiosis
mitosis
- replace old or worn out cells (somatic cells), - results in diploid cells (complete set of genetic chromosomes 46)
-continuous process
miosis
- produces gametes, egg and sperm,
(sperm produced- testes, eggs produced- ovaries)
- produces gametes, therefore only 23 chromosomes (haploid cells)
stage 1 of mitosis
interphase
- DNA molecules in the nucleus form exact copies of each other
stage 2 of mitosis
prophase
- nuclear membrane starts top break down
- chromosomes are now visible
- spindle fibres form
stage 3 of mitosis
metaphase
- chromosomes align in the middle o fat e cell
- spindle fibres attach to the centromere (middle of the chromosome)
stage 4 of mitosis
anaphase
- spindle fibres start to pull the chromosomes part to become chromatids
stage 5 of mitosis
telophase
- nuclear membrane starts to form
- spindle fibres disappear
stage 6 of mitosis
cytokinesis
- cell divides into two new cells called daughter cells, each containing 46 chromosomes
asexual reproduction
- form of reproduction where only one parent produces offspring
- no joining of sperm or egg
- offspring are identical to parents
examples- hydras, grasses- known as runners that grow along the ground surface
explain two divisions of meiosis
prophase l, metaphase l, anaphase l, telophase l = 2 cells, 46 chromosomes
prophase ll, metaphase ll, anaphase ll, telophase ll = 4 cells, 23 chromosomes
