False Primary Producers must form the largest base, because if there is a shortage of them, then there will be only a small amount for all others. This i guess can be called the Doppler's effect
('bit of history in here)
hope this helps
Answer:
a. + glucose, + lactose = On
b. - glucose, - lactose = Off
c. + glucose, - lactose = Off
d. - glucose, + lactose = On
Explanation:
Lac operon has both types of control, repressible and inducible.
Whenever glucose level is low in the cell, an enzyme known as adenylyl cyclase raises the level of cAMP which forms a dimer with CRP protein and they both act as activator of lac operon and cause expression.
Apart from this, when lactose is present in the cell, β-galactosidase enzyme metabolizes lactose to form allolactose which causes allosteric repulsion in the lac repressor and causes its removal from the operator. As soon as repressor is removed lac operon gets activated.
In wild type lac operons, the expression of lac operon occurs when glucose level is low in the cell and lactose is present but in this mutant presence or absence of glucose will not make a difference because CRP will bind Plac promoter independent of cAMP level i.e. activator CRP will work even in high glucose concentration. If lactose is present then lac operon will always express so in option 'a & d' lac operon will express but in option 'b & c' it will not express.
Answer:
- light positioning: c. Extrinsic muscles; d. Pupil
- sensory processing: a. Photoreceptors; b. Occipital cortex; e. Bipolar cells
Explanation:
Extrinsic (extraocular) muscles are muscles that modulate both eye movement and position, whereas intrinsic (intraocular) muscles are muscles that focus the eye and control how much light enters into the eye. The pupil is the black center of the eye within the iris through which light passes before being focused onto the retina. Photoreceptors are specialized neurons located in the retina that respond to light, converting it into electrical signals that can stimulate biological processes. Photoreceptors in the retina are divided into two categories 1-rods (responsible for vision at low light levels), and 2-cones (active at higher light). Bipolar cells are neurons that transmit signals from the photoreceptors to the ganglion cells, thereby processing light signals received from rods and cones. The occipital cortex is a brain region that represents the visual processing center and contains most of the anatomical region of the visual cortex.
Complex organisms need cells that can perform many different functions. they need to be supported on a cellular level. Without specialized cells you they won't be able to perform different functions.
