Svience biology Flashcards
What does the phosphate group do?
involved with the sugar in helping hold together the DNA sugar
What is the big bang theory?
a theory stating that their was nothing until a singularity occurred and the universe expanded outwards evenly
What are examples of the atmosphere?
- thin compared to earth
- air, oxygen and gases
- 78% nitrogen, 21% oxygen, 0.9% argon and 0.1% other
What makes carbon dioxide special?
unlike nitrogen and oxygen (2 atoms) it has 3 atoms allowing it to absorb/trap heat
What is a planetary nebula?
old red giants continue to expand until its outer shell gets ejected making a ring shaped nebula
What is cell division?
the process in which parent cell divides into 2 or more daughter cells
Is the the natural greenhouse effect vital?
yes, to maintain earth’s temperatures and ensure it’s habitable
Whats the radius of a neutron star?
10km
Where does a stars energy come from?
nuclear fusion of mainly hydrogen atoms.
What type of letters are dominant and recessive alleles represented by?
dominant - capital
recessive - lowercase
What is cell specialisation?
The process where generic cells transform into specialised cells with defined roles.
What are examples of the lithosphere?
- earth’s crust
- cool part of mantle
- mountains
- continents
- ocean floor
- rocks, sands, minerals and soil
What type of bond connects the nitrogenous base with a pentose sugar?
covalent
Under what conditions does a main sequence star become a red giant?
smaller than 8x suns mass
What is natural selection?
the process in which an environmental factor acts on a population and results in some organisims having greater chance of survial and producing more off spring than others
What is a supernova?
the expanding shock wave that occurs when supergiants are destroyed by a titanic explosion leaving only the core
What are galaxies?
clusters of relatively close stars, dust and other remnants that are held together by gravity.
What is gravity?
a weak force, that over billions of years have attracted stars to clump together to form a galaxy.
What are alleles?
- an alternative form of gene
- every trait has 2 alleles
- expressed as dominant of recessive
What is short wave radiation?
radiation directly from the sun, converts to heat when it heats an object
Under what conditions does the remaining supergiant core become a neutron star?
less than 3x suns mass
What is a black dwarf?
once a white dwarf cools enough it becomes invisible thus becoming a black dwarf
What does the Lithosphere include?
solid earth
What are genes?
- the sequence of DNA that codes for protein thus determines a trait
- each chromosome contains many genes that code for different traits
Does genetic variation increase or decrease genetic fitness?
both
What is mitosis?
a type of cell division done by most of your body
What are the 4 symbols of a pedigree and their meanings?
circle - female
square - male
coloured - affected
slash - dead
What does the inside of chromosomes act like?
instructions to teach cells how to function and replicate
Can atoms be destroyed or created?
neither
What are the two things main sequence stars can become?
red giant and supergiants
What is evolution?
the change in a species over many generations resulting in the formation of a new species
Why is mitosis important?
growth and repair
What are the 3 main influences on climate?
- earths surface - how much sun energy will be reflected back
- gases in atmosphere - how much and what types
- orientation of the earth - angle of suns radiation effects intensity (more steep = more intense vice versa)
What is an example of speciation?
- VARIATION in giraffe necks
- giraffes ISOLATED to environment and struggle to survive
- the phenotype best suited to environment is SELECTED by environment and passed on
What is earths nearest star?
sun
What does the Atmosphere include?
the gases that surround earth
Whats a genotype?
genetic makeup of an organism (allele)
What are the two chromosomes females and males have?
females - XX
males - XY
What is fusion?
combination of atoms
What do stem cells replace?
worn out cells
What is a pedigree?
a diagram that shows the relationship between parents and children over generation and how a trait is passed down
Whats the mass of a neutron star?
5x the sun
Whats the carbon cycle?
- plants absorb carbon
- animals eat plants and carbon
- carbon returns back to atmosphere from dead plants, animals and poo
- carbon stored underground becomes coal
- when coal is used it returns back to atmosphere
- carbon can go into ocean
- plants return carbon through plant respiration
What is the star colour/temperature or spectral class guide?
O, B, A, F, G, K, M
What are chromosomes
small structures of tightly coiled DNA segments made of DNA and protein
Is cytokinesis and interphase part of mitosis?
no
Why do 3 atoms allow molecules to absorb heat?
allow vibrations in more ways
How many stars are main sequence stars?
90%
How many out of the 46 chromosomes actually determine the gender?
2
How many pairs of chromosomes are there?
23
What are traits?
- a specific characteristic that varies with different people
- genes coded define our traits
- physical, behavioural, predisposition and medical
What are cells?
- basic building blocks of organelles
- vary in size, shape and function
How have humans altered the greenhouse effect?
unbalanced CO2 in atmosphere, the earth can no longer keep up with the release of greenhouse gases and so they remain in the atmosphere with the trapped heat causing the climate to change and the globe to warm